Manga creators Machiko Satonaka (Lady Ann) and Tetsuya Chiba (Ashita no Joe) were among several other manga creators that held a press conference on Monday. The conference was held to express their opposition against the proposed legislation in Metropolitan Tokyo that would restrict sexually provocative visual depictions of characters who appear or sound like they are younger than 18 years old. The group presented a written statement that opposed the measure. A number of prominent manga creators signed the statement, including Fujiko Fujio A (Doraemon), Moto Hagio (They Were Eleven), and Takao Saito (Golgo 13).

NicoNico Douga presented a live video feed of the event, while television network TBS posted an excerpt. Freelance writer Shibui later posted photographs of the list of names attached to the opposition statement. The full list of creators attached is as follows:

• Fujiko Fujio A
• Takao Saito
• Juzo Yamasaki
• Kenichi Kitami
• Mitsuru Adachi
• Rumiko Takahashi
• Gosho Aoyama
• Moto Hagio
• Michiyo Akaishi
• Wakuni Akisato
• Hiroshi Motomiya
• Makoto Ogino
• Big Joe
• Takeshi Omi
• Uzuki Nakamura
• Yudetamago
• Takashi Sano
• Tetsuya Chiba
• Kenshi Hirokane
• Kaiji Kawaguchi
• Makoto Kobayashi
• Takeshi Maekawa
• Hiroki Yagami
• Ken Akamatsu
• Tohru Fujisawa
• Kazuki Yamamoto
• Kanji Sorasaki
• Naoki Serizawa
• Tetsuya Koshiba
• Uchu Nishikawa
• Waki Yamato
• Jun Fukami
• Mariko Nakamura
• Nami Akimoto
• Yasuyuki Kunitomo
• Ryohei Saigan
• Jun Hayase
• Satosumi Takaguchi
• Kaworu Watashiya
• Masako Watanabe
• Keisuke Itagaki
• Kenji Hamaoka
• Yoshikazu Yasuhiko
• Takayuki Yamaguchi
• Yoshiaki Tabata
• Yousuke Takahashi
• Akihito Yoshitomi
• Yuki Yogo
• Yasuhiro Imagawa
• Yasunari Toda
• Kenetsu Satou
• Hiroyuki Yoshino
• Masahiro Itosugi
• Kenji Yamamoto
• Koban Sameda
• Makoto Uezu
• Shigeru Morita
• Hiraku Kaneko
• Munenori Nawa
• Akita Shoten
• Shonen Gahosha
• Kadokawa Shoten
• Shinchosha
• Kodansha
• Hakusensha
• Shueisha
• Futabasha
• Shogakukan
• Leed

Since the press conference, several other individuals voiced their opposition to the legislation, including the following:

• Voice actress Haruna Ikezawa (Futari wa Pretty Cure, Maria Watches Over Us)
• Lawyer Takashi Yamaguchi
• Manga creator Yoshitoshi ABe (Haibane Renmei, Serial Experiments Lain)
• Manga creator Yun Kouga (Gestalt, Mobile Suit Gundam 00)
• Manga creator Yasuhiro Nightow (Trigun)
• Manga creator Go Nagai (Cutey Honey, Getter Robo)
• Manga creator Nanae Sasaya
• Manga creator Keiko Takemiya (Toward the Terra)
• Manga creator Kohei Nishino
• Several Manga Departmant professors at Kyoto Seika University

Later that day, Editor-in-chief of Shogakukan's Monthly Ikki magazine Hideki Egami asked manga creators to respond on Twitter if they opposed the legislation. The list as of 6:00AM Eastern time the following day includes the following:

• Makoto Sato (Todoroke! Tekkotsu-kun)
• Syuji Takeya (Astral Project - Tsuki no Hikari)
• Shinji Inamitsu (Deru Toko Demasho!)
• Miki Tori (Anywhere But Here)
• est em (Seduce Me After the Show)
• Hiroko Matsuda
• Hideo Shinangawa (Monthly Spirits magazine)
• Hisashi Eguchi (Stop! Hibari-kun)
• Banana Nangoku
• Masaharu Inoue
• Natsuki Sugihara/Kirico Higashizato (Love Recipe)
• Toru Sugita
• Yuko Umino
• Maico Shioya
• Hozumi
• Yukio Tamai
• Ryoji Hido (Heroes Are Extinct!)
• Cosine
• Juichi Iogi
• Miyuki Noma
• Hidefumi Akino
• Ume (Takahiro Ozawa/Asako Seo)
• Kagekusa Kimi
• Takashi Kisaki
• Miou Takaya

Also on Monday, translator and production coordinator Dan Kanemitsu led 30 comic book authors, translators, and editors to the Tokyo Metropolitan Assembly to speak with four legislators directly. The following industry professionals attended the meeting:

• Yoshitoh Asari
• Keitaro Arima
• Yuji Kaida
• Aya Kaida
• Hotaru Umino
• Benkyo Tamaoki
• Jun'ichi Inoue
• Hisao Tamaki
• Natsuko Mori
• Rasenjin Hayami
• Tsubura Hase
• Takeshi Nogami
• Yohane Yamamoto
• Kozo Shimokata
• Ezuroku
• Hironori Hazuki
• Tsutomu Shindo
• Hiroyuki Sanazura
• Kiyoshi Shimizu
• Kaoru Nagayama
• Taku Koide
• Cosine
• Kosetsu Tateno
• Nagito Mikoshiro