A graduate of the Meiji Gakuin University School of Law and a native of Sugamo, he previously served as a secretary to SDP chair Mizuho Fukushima, and founded the gay male support organization Peer Friends in 2004.

He has since been active in the Japanese LGBT rights movement and has appeared in various series, including NHK's Heart-to-Heart,[3] and has participated in the Tokyo Pride Parade.

[4] The first openly gay candidate for leadership of a sitting parliamentary party in Japanese history, Ishikawa was recognized after the election by an editorial in The Japan Times as one who could both "be a valuable asset for the SDP" and "help channel the voices of marginalized people, including irregularly employed workers and members of the gay community, to ensure that they are reflected in local and national politics".

[7] In the middle of the night on March 20, 2020, at Shinjuku Ni-chōme, the biggest gay village in Tokyo, Japan,[8] Ishikawa suddenly filmed a police car on patrol.

Ishikawa stated the reason for his participation, "At the National Diet, after receiving an explanation from the Kurdish man himself, and after reviewing the video of the questioning, I determined that there was unfair treatment, such as the fact that the police officers took away the man's cell phone while he was recording a video, and that the police officers then attempted to delete the video.”[10] Shortly before Shinzo Abe announced his resignation from the position of Prime Minister of Japan on August 28, 2020, citing worsening ulcerative colitis, Ishikawa posted a tweet calling for accountability, saying that Abe would not be allowed to hide behind the clouds.