Yasuhito Tanaka
Publication Activity (10 Years)
Years Active: 2019-2024
Publications (10 Years): 62
Publications (10 Years): 62
Publications
- Hidenori Toyoda, Toshifumi Tada, Haruki Uojima, Akito Nozaki, Makoto Chuma, Koichi Takaguchi, Atsushi Hiraoka, Hiroshi Abe, Ei Itobayashi, Kentaro Matsuura, Masanori Atsukawa, Tsunamasa Watanabe, Noritomo Shimada, Makoto Nakamuta, Motoyuki Kojima, Kunihiko Tsuji, Shigeru Mikami, Toru Ishikawa, Satoshi Yasuda, Akemi Tsutsui, Taeang Arai, Takashi Kumada, Yasuhito Tanaka, Junko Tanaka, Kazuaki Chayama
- Takahiro Nakashima, Shigeru Kusumoto, Takashi Ishida, Chie Kato, Shinya Hagiwara, Tomoko Narita, Ayako Masaki, Asahi Ito, Masaki Ri, Hirokazu Komatsu, Hiroshi Inagaki, Yasuhito Tanaka, Shinsuke Iida
- Takehisa Watanabe, Sanae Hayashi, Yan Zhaoyu, Hiroki Inada, Katsuya Nagaoka, Masakuni Tateyama, Yasuhito Tanaka
- Hideaki Miyamoto, Yasuteru Kondo, Ei Itobayashi, Masayoshi Uehara, Atsushi Hiraoka, Masatoshi Kudo, Satoru Kakizaki, Tatehiro Kagawa, Satoshi Miuma, Takanori Suzuki, Kazuhiro Sugi, Koichi Suyama, Toru Beppu, Hidenori Toyoda, Hitoshi Yoshiji, Haruki Uojima, Shiho Miyase, Kaori Inoue, Akihiro Tamori, Takanori Ito, Shigeo Shimose, Goki Suda, Tsuguru Hayashi, Masaya Onishi, Satoshi Narahara, Takehisa Watanabe, Masaaki Iwatsuki, Satoshi Fukushima, Yasuhito TanakaEvaluation of the associations of interlukin-7 genetic variants with toxicity and efficacy of immune checkpoint inhibitors: A replication study of a Japanese population, based on the findings of a European genome-wide association study. Hepatology research : the official journal of the Japan Society of Hepatology (2024)
- Shota Harai, Susumu Hijioka, Reiko Yamada, Takeshi Ogura, Mitsuharu Fukasawa, Atsushi Okuda, Hideyuki Horike, Dai Inoue, Masanari Sekine, Yusuke Ishida, Takehiko Koga, Hidetoshi Kitamura, Yasuhito Tanaka, Motohiro Yoshinari, Katsumasa Kobayashi, Mark Chatto, Daiki Yamashige, Yuki Kawasaki, Yoshikuni Nagashio, Takuji Okusaka
- Hidenori Toyoda, Toshifumi Tada, Haruki Uojima, Akito Nozaki, Makoto Chuma, Koichi Takaguchi, Atsushi Hiraoka, Hiroshi Abe, Ei Itobayashi, Kentaro Matsuura, Masanori Atsukawa, Tsunamasa Watanabe, Noritomo Shimada, Makoto Nakamuta, Motoyuki Kojima, Kunihiko Tsuji, Shigeru Mikami, Toru Ishikawa, Satoshi Yasuda, Akemi Tsutsui, Taeang Arai, Takashi Kumada, Yasuhito Tanaka, Junko Tanaka, Kazuaki Chayama
- Sayoko Tayama, Yoki Furuta, Miyuki Morito, Hideaki Naoe, Daiki Yoshii, Yasuyuki Uchida, Koichiro Yoshimaru, Yuji Miyamoto, Tomoaki Taguchi, Yasuhito Tanaka
- Takako Inoue, Shintaro Yagi, Yasuhito Tanaka
- Shota Harai, Susumu Hijioka, Reiko Yamada, Takeshi Ogura, Mitsuharu Fukasawa, Atsushi Okuda, Hideyuki Horike, Dai Inoue, Masanari Sekine, Yusuke Ishida, Takehiko Koga, Hidetoshi Kitamura, Yasuhito Tanaka, Motohiro Yoshinari, Katsumasa Kobayashi, Mark Chatto, Daiki Yamashige, Yuki Kawasaki, Yoshikuni Nagashio, Takuji Okusaka
- Daniel Q Huang, Joseph K Hoang, Rubayet Kamal, Pei-Chien Tsai, Hidenori Toyoda, Ming-Lun Yeh, Satoshi Yasuda, Jennifer Leong, Mayumi Maeda, Chung-Feng Huang, Dae Won Jun, Masatoshi Ishigami, Yasuhito Tanaka, Haruki Uojima, Eiichi Ogawa, Hiroshi Abe, Yao-Chun Hsu, Cheng-Hao Tseng, Manaf Alsudaney, Ju Dong Yang, Yoko Yoshimaru, Takanori Suzuki, Joanne K Liu, Charles Landis, Chia-Yen Dai, Jee-Fu Huang, Wan-Long Chuang, Myron Schwartz, Yock Young Dan, Carlos O Esquivel, Andrew Bonham, Ming-Lung Yu, Mindie H Nguyen
- Sayoko Tayama, Yoki Furuta, Miyuki Morito, Hideaki Naoe, Daiki Yoshii, Yasuyuki Uchida, Koichiro Yoshimaru, Yuji Miyamoto, Tomoaki Taguchi, Yasuhito Tanaka
- Daniel Q Huang, Joseph K Hoang, Rubayet Kamal, Pei-Chien Tsai, Hidenori Toyoda, Ming-Lun Yeh, Satoshi Yasuda, Jennifer Leong, Mayumi Maeda, Chung-Feng Huang, Dae Won Jun, Masatoshi Ishigami, Yasuhito Tanaka, Haruki Uojima, Eiichi Ogawa, Hiroshi Abe, Yao-Chun Hsu, Cheng-Hao Tseng, Manaf Alsudaney, Ju Dong Yang, Yoko Yoshimaru, Takanori Suzuki, Joanne K Liu, Charles Landis, Chia-Yen Dai, Jee-Fu Huang, Wan-Long Chuang, Myron Schwartz, Yock Young Dan, Carlos O Esquivel, Andrew Bonham, Ming-Lung Yu, Mindie H Nguyen
- Takanori Suzuki, Kentaro Matsuura, Yuta Suzuki, Fumihiro Okumura, Yoshihito Nagura, Satoshi Sobue, Sho Matoya, Tomokatsu Miyaki, Yoshihide Kimura, Atsunori Kusakabe, Satoshi Narahara, Takayuki Tokunaga, Katsuya Nagaoka, Shuko Murakami, Takako Inoue, Keita Kuroyanagi, Hayato Kawamura, Kei Fujiwara, Shunsuke Nojiri, Hiromi Kataoka, Yasuhito Tanaka
- Takehisa Watanabe, Sanae Hayashi, Yan Zhaoyu, Hiroki Inada, Katsuya Nagaoka, Masakuni Tateyama, Yasuhito Tanaka
- Takehisa Watanabe, Sanae Hayashi, Yan Zhaoyu, Hiroki Inada, Katsuya Nagaoka, Masakuni Tateyama, Yasuhito Tanaka
- Hiroki Inada, Hideaki Miyamoto, Satoru Shinriki, Hisanobu Oda, Satoshi Narahara, Motohiro Yoshinari, Katsuya Nagaoka, Daiki Yoshii, Kotaro Fukubayashi, Hiromitsu Hayashi, Hideo Baba, Kisato Nosaka, Yasuhito Tanaka
- Takako Inoue, Shintaro Yagi, Yasuhito Tanaka
- Takehisa Watanabe, Sanae Hayashi, Yan Zhaoyu, Hiroki Inada, Katsuya Nagaoka, Masakuni Tateyama, Yasuhito Tanaka
- Takako Inoue, Shintaro Yagi, Yasuhito Tanaka
- Hayato Kawamura, Kentaro Matsuura, Koichi Ito, Tokio Sugiura, Takanori Suzuki, Kei Fujiwara, Hiromi Kataoka, Yasuhito Tanaka
- Kenshi Matsuno, Hideaki Miyamoto, Miki Shimoda, Ryosuke Gushima, Katsuya Nagaoka, Mayuko Ohuchi, Yuji Miyamoto, Kohei Ohkura, Yoshiki Mikami, Yasuhito Tanaka
- Sayoko Tayama, Yoki Furuta, Miyuki Morito, Hideaki Naoe, Daiki Yoshii, Yasuyuki Uchida, Koichiro Yoshimaru, Yuji Miyamoto, Tomoaki Taguchi, Yasuhito Tanaka
- Emi Sometani, Hayato Hikita, Kazuhiro Murai, Hidenori Toyoda, Satoshi Tanaka, Tsugiko Oze, Jihyun Sung, Akiyoshi Shimoda, Makoto Fukuoka, Satoshi Shigeno, Keisuke Fukutomi, Kumiko Shirai, Yuki Tahata, Yoshinobu Saito, Akira Nishio, Kunimaro Furuta, Takahiro Kodama, Ryotaro Sakamori, Tomohide Tatsumi, Eiji Mita, Akihiro Umezawa, Yasuhito Tanaka, Tetsuo Takehara
- Daniel Q Huang, Joseph K Hoang, Rubayet Kamal, Pei-Chien Tsai, Hidenori Toyoda, Ming-Lun Yeh, Satoshi Yasuda, Jennifer Leong, Mayumi Maeda, Chung-Feng Huang, Dae Won Jun, Masatoshi Ishigami, Yasuhito Tanaka, Haruki Uojima, Eiichi Ogawa, Hiroshi Abe, Yao-Chun Hsu, Cheng-Hao Tseng, Manaf Alsudaney, Ju Dong Yang, Yoko Yoshimaru, Takanori Suzuki, Joanne K Liu, Charles Landis, Chia-Yen Dai, Jee-Fu Huang, Wan-Long Chuang, Myron Schwartz, Yock Young Dan, Carlos O Esquivel, Andrew Bonham, Ming-Lung Yu, Mindie H Nguyen
- Daiyu Matsubara, Naotaka Kugiyama, Katsuya Nagaoka, Motohiro Yoshinari, Shunpei Hashigo, Keita Shimata, Yoshitaka Tamura, Toshinori Hirai, Taizo Hibi, Yasuhito Tanaka
- Yoko Yoshimaru, Katsuya Nagaoka, Kentaro Tanaka, Satoshi Narahara, Hiroki Inada, Sotaro Kurano, Takayuki Tokunaga, Estuko Iio, Takehisa Watanabe, Hiroko Setoyama, Masakuni Tateyama, Koji Yoshida, Takuya Tsunoda, Yusuke Nakamura, Motohiko Tanaka, Yutaka Sasaki, Yasuhito Tanaka
- Hiroko Setoyama, Nao Nishida, Shintaro Nagashima, Ko Ko, Taiji Yamazoe, Yasuhito Tanaka, Masashi Mizokami, Junko Tanaka, Tatsuya Kanto
- Yushi Kawakami, Ryu Ishihara, Kenshi Matsuno, Kotaro Waki, Satoki Shichijo, Shunsuke Yoshii, Takashi Kanesaka, Sachiko Yamamoto, Toshio Uraoka, Koji Higashino, Noriya Uedo, Tomoki Michida, Yasuhito Tanaka
- Takayuki Tokunaga, Masakuni Tateyama, Yasuteru Kondo, Satoshi Miuma, Shiho Miyase, Kentaro Tanaka, Satoshi Narahara, Hiroki Inada, Sotaro Kurano, Yoko Yoshimaru, Katsuya Nagaoka, Takehisa Watanabe, Hiroko Setoyama, Kotaro Fukubayashi, Motohiko Tanaka, Yasuhito Tanaka
- Yoshihito Nagura, Takanori Suzuki, Kentaro Matsuura, Shintaro Ogawa, Hayato Kawamura, Kayoko Kuno, Kei Fujiwara, Shunsuke Nojiri, Katsuya Nagaoka, Etsuko Iio, Takehisa Watanabe, Hiromi Kataoka, Yasuhito Tanaka
- Takayuki Tokunaga, Masakuni Tateyama, Yasuteru Kondo, Satoshi Miuma, Shiho Miyase, Kentaro Tanaka, Satoshi Narahara, Hiroki Inada, Sotaro Kurano, Yoko Yoshimaru, Katsuya Nagaoka, Takehisa Watanabe, Hiroko Setoyama, Kotaro Fukubayashi, Motohiko Tanaka, Yasuhito Tanaka
- Naotaka Kugiyama, Shunpei Hashigo, Katsuya Nagaoka, Takehisa Watanabe, Shinya Ushijima, Yukiko Uramoto, Motohiro Yoshinari, Jun Morinaga, Ryosuke Gushima, Masakuni Tateyama, Motohiko Tanaka, Hideaki Naoe, Yasuhiko Sugawara, Taizo Hibi, Yasuhito Tanaka
- Yoki Furuta, Ryosuke Gushima, Hideaki Naoe, Munenori Honda, Yuiko Tsuruta, Katsuya Nagaoka, Takehisa Watanabe, Masakuni Tateyama, Nahoko Fujimoto, Shinya Hirata, Eiko Miyagawa, Komei Sakata, Yumiko Mizuhashi, Mikako Iwakura, Masayuki Murai, Masao Matsuoka, Yoshihiro Komohara, Yasuhito Tanaka
- Yoki Furuta, Ryosuke Gushima, Hideaki Naoe, Munenori Honda, Yuiko Tsuruta, Katsuya Nagaoka, Takehisa Watanabe, Masakuni Tateyama, Nahoko Fujimoto, Shinya Hirata, Eiko Miyagawa, Komei Sakata, Yumiko Mizuhashi, Mikako Iwakura, Masayuki Murai, Masao Matsuoka, Yoshihiro Komohara, Yasuhito Tanaka
- Takehisa Watanabe, Sanae Hayashi, Yasuhito Tanaka
- Anna Nakanishi, Hiroki Okumura, Tadahiro Hashita, Aya Yamashita, Yuka Nishimura, Chihiro Watanabe, Sakina Kamimura, Sanae Hayashi, Shuko Murakami, Kyoko Ito, Takahiro Iwao, Akari Ikeda, Tomoyasu Hirose, Toshiaki Sunazuka, Yasuhito Tanaka, Tamihide Matsunaga
- Shinya Hagiwara, Shigeru Kusumoto, Takako Inoue, Shintaro Ogawa, Tomoko Narita, Asahi Ito, Masaki Ri, Hirokazu Komatsu, Takanori Suzuki, Kentaro Matsuura, Shintaro Yagi, Atsushi Kaneko, Katsumi Aoyagi, Shinsuke Iida, Yasuhito Tanaka
- Takanori Suzuki, Kentaro Matsuura, Yoshihito Nagura, Shintaro Ogawa, Kei Fujiwara, Shunsuke Nojiri, Takehisa Watanabe, Hiromi Kataoka, Yasuhito Tanaka
- Korenobu Hayama, Masanori Atsukawa, Akihito Tsubota, Chisa Kondo, Motoh Iwasa, Hiroshi Hasegawa, Koichi Takaguchi, Akemi Tsutsui, Haruki Uojima, Hisashi Hidaka, Hironao Okubo, Tatsuya Suzuki, Kentaro Matsuura, Toshifumi Tada, Naoto Kawabe, Joji Tani, Akihiro Morishita, Toru Ishikawa, Yoshitaka Arase, Yoshihiro Furuichi, Keizo Kato, Kazuhito Kawata, Makoto Chuma, Akito Nozaki, Atsushi Hiraoka, Tsunamasa Watanabe, Tatehiro Kagawa, Hidenori Toyoda, Nobuhiko Taniai, Hiroshi Yoshida, Yasuhito Tanaka, Katsuhiko Iwakiri, null null
- Kazuhito Kawata, Masanori Atsukawa, Kazuyoshi Ohta, Takeshi Chida, Hidenao Noritake, Taeang Arai, Katsuhiko Iwakiri, Satoshi Yasuda, Hidenori Toyoda, Tomomi Okubo, Atsushi Hiraoka, Tsunamasa Watanabe, Haruki Uojima, Akito Nozaki, Joji Tani, Akihiro Morishita, Fujito Kageyama, Yuzo Sasada, Masamichi Nagasawa, Masahiro Matsushita, Tatsuki Oyaizu, Shigeru Mikami, Tadashi Ikegami, Hiroshi Abe, Kentaro Matsuura, Yasuhito Tanaka, Akihito Tsubota
- Yoshihito Nagura, Kentaro Matsuura, Etsuko Iio, Koji Fujita, Takako Inoue, Akihiro Matsumoto, Eiji Tanaka, Shuhei Nishiguchi, Jong-Hon Kang, Takeshi Matsui, Masaru Enomoto, Hiroki Ikeda, Tsunamasa Watanabe, Chiaki Okuse, Masataka Tsuge, Masanori Atsukawa, Masakuni Tateyama, Tomoya Kataoka, Yasuhito Tanaka
- Takanori Suzuki, Kentaro Matsuura, Kenji Urakabe, Fumihiro Okumura, Hayato Kawamura, Satoshi Sobue, Sho Matoya, Tomokatsu Miyaki, Yoshihide Kimura, Daisuke Kato, Atsunori Kusakabe, Yoshito Tanaka, Atsushi Ozasa, Yoshihito Nagura, Kei Fujiwara, Shunsuke Nojiri, Shinya Hagiwara, Shigeru Kusumoto, Takako Inoue, Yasuhito Tanaka, Hiromi Kataoka
- Takanori Suzuki, Takako Inoue, Kentaro Matsuura, Shigeru Kusumoto, Shinya Hagiwara, Shintaro Ogawa, Shintaro Yagi, Atsushi Kaneko, Kei Fujiwara, Takehisa Watanabe, Katsumi Aoyagi, Yukitomo Urata, Akihiro Tamori, Hiromi Kataoka, Yasuhito Tanaka
- Michihiro Yoshida, Hiroshi Yukawa, Kazuki Hayashi, Itaru Naitoh, Katsuyuki Miyabe, Yasuki Hori, Makoto Natsume, Naruomi Jinno, Akihisa Kato, Kenta Kachi, Go Asano, Hidenori Sahashi, Tadashi Toyohara, Kayoko Kuno, Yusuke Kito, Hiromu Kondo, Atsuyuki Hirano, Fumihiro Okumura, Kaiki Anbe, Yoshinobu Baba, Tomoya Kataoka, Yasuhito Tanaka
- Takanori Suzuki, Kentaro Matsuura, Yoshihito Nagura, Etsuko Iio, Shintaro Ogawa, Kei Fujiwara, Shunsuke Nojiri, Hiromi Kataoka, Yasuhito Tanaka
- Satoshi Narahara, Takehisa Watanabe, Katsuya Nagaoka, Nahoko Fujimoto, Yoki Furuta, Kentaro Tanaka, Takayuki Tokunaga, Takeshi Kawasaki, Yoko Yoshimaru, Hiroko Setoyama, Kentaro Oniki, Junji Saruwatari, Masakuni Tateyama, Hideaki Naoe, Motohiko Tanaka, Yasuhito Tanaka, Yutaka Sasaki
- Ian Baudi, Masanori Isogawa, Federica Moalli, Masaya Onishi, Keigo Kawashima, Yuji Ishida, Chise Tateno, Yusuke Sato, Hideyoshi Harashima, Hiroyasu Ito, Tetsuya Ishikawa, Takaji Wakita, Matteo Iannacone, Yasuhito Tanaka
- Takayuki Tokunaga, Masakuni Tateyama, Kentaro Tanaka, Satoshi Narahara, Hiroki Inada, Sotaro Kurano, Sanae Hayashi, Yoko Yoshimaru, Katsuya Nagaoka, Takehisa Watanabe, Hiroko Setoyama, Motohiko Tanaka, Yasuhito Tanaka
- Takehisa Watanabe, Takako Inoue, Yasuhito Tanaka
- Takako Inoue, Yui Funatsu, Masaya Ohnishi, Masanori Isogawa, Keigo Kawashima, Masaru Tanaka, Kei Moriya, Hideto Kawaratani, Rie Momoda, Etsuko Iio, Hidewaki Nakagawa, Yutaka Suzuki, Kentaro Matsuura, Kei Fujiwara, Hirokazu Takahashi, Hitoshi Yoshiji, Jiro Nakayama, Yasuhito Tanaka
- Tsuyoshi Matsui, Susumu Hamada-Tsutsumi, Yutaka Naito, Masanori Nojima, Etsuko Iio, Akihiro Tamori, Shoji Kubo, Tatsuya Ide, Yasuteru Kondo, Yuichiro Eguchi, Atsumasa Komori, Yuji Morine, Mitsuo Shimada, Tohru Utsunomiya, Ken Shirabe, Koichi Kimura, Yoichi Hiasa, Natthaya Chuaypen, Pisit Tangkijvanich, Aya Naiki-Ito, Satoru Takahashi, Takahiro Ochiya, Yasuhito Tanaka
- Kazushi Fujimoto, Youhei Yamaguchi, Ryo Urano, Wataru Shinoda, Tetsuya Ishikawa, Katsumi Omagari, Yasuhito Tanaka, Atsushi Nakagawa, Susumu Okazaki
- Hideto Kawaratani, Hiromi Sawai, Masaya Onishi, Tomomi Kogiso, Noritomo Shimada, Haruki Uojima, Tomoaki Nakajima, Naoki Matsumoto, Kenichi Ikejima, Toru Ishikawa, Shuji Terai, Hiroyuki Motoyama, Atsumasa Komori, Noboru Hirashima, Satoru Saito, Yuichiro Eguchi, Masanori Nojima, Yosuke Kawai, Masakuni Tateyama, Hitoshi Yoshiji, Yasuhito Tanaka
- Masanori Atsukawa, Akihito Tsubota, Chisa Kondo, Hidenori Toyoda, Makoto Nakamuta, Koichi Takaguchi, Tsunamasa Watanabe, Atsushi Hiraoka, Haruki Uojima, Toru Ishikawa, Motoh Iwasa, Toshifumi Tada, Akito Nozaki, Makoto Chuma, Shinya Fukunishi, Toru Asano, Chikara Ogawa, Hiroshi Abe, Keizo Kato, Naoki Hotta, Toshihide Shima, Kentaro Matsuura, Shigeru Mikami, Yoshihiko Tachi, Shinichi Fujioka, Hironao Okubo, Noritomo Shimada, Joji Tani, Akihiro Morishita, Isao Hidaka, Akio Moriya, Kunihiko Tsuji, Takehiro Akahane, Tomomi Okubo, Taeang Arai, Michika Kitamura, Kiyoshi Morita, Kazuhito Kawata, Yasuhito Tanaka, Takashi Kumada, Katsuhiko Iwakiri, null null
- Natthaya Chuaypen, Salyavit Chittmittrapap, Anchalee Avihingsanon, Surachate Siripongsakun, Jongkonnee Wongpiyabovorn, Natthaporn Tanpowpong, Yasuhito Tanaka, Pisit Tangkijvanich
- Masanori Atsukawa, Akihito Tsubota, Chisa Kondo, Sawako Uchida-Kobayashi, Koichi Takaguchi, Akemi Tsutsui, Akito Nozaki, Makoto Chuma, Isao Hidaka, Tsuyoshi Ishikawa, Motoh Iwasa, Yasuyuki Tamai, Maki Tobari, Kentaro Matsuura, Yoshihito Nagura, Hiroshi Abe, Keizo Kato, Kenta Suzuki, Tomomi Okubo, Taeang Arai, Norio Itokawa, Hidenori Toyoda, Masaru Enomoto, Akihiro Tamori, Yasuhito Tanaka, Norifumi Kawada, Yoshiyuki Takei, Katsuhiko Iwakiri
- Kota Tsuruya, Kazuya Anzai, Shunsuke Shioyama, Ayano Ito, Yoshitaka Arase, Shunji Hirose, Yasuhito Tanaka, Hidekazu Suzuki, Tatehiro Kagawa
- Jia-Horng Kao, Tsung-Hui Hu, Ji-Dong Jia, Masayuki Kurosaki, Young Suk Lim, Han-Chieh Lin, Dong Hyun Sinn, Yasuhito Tanaka, Vincent Wai-Sun Wong, Man Fung Yuen
- Susumu Hamada-Tsutsumi, Yutaka Naito, Seiichi Sato, Akinori Takaoka, Keigo Kawashima, Masanori Isogawa, Takahiro Ochiya, Yasuhito Tanaka
- Masashi Iwamoto, Wakana Saso, Ryuichi Sugiyama, Koji Ishii, Mio Ohki, Shushi Nagamori, Ryosuke Suzuki, Hideki Aizaki, Akihide Ryo, Ji-Hye Yun, Sam-Yong Park, Naoko Ohtani, Masamichi Muramatsu, Shingo Iwami, Yasuhito Tanaka, Camille Sureau, Takaji Wakita, Koichi Watashi