恋愛裁判 (Love Trial) is a Vocaloid track by the prominent producer 40mP, sung by Hatsune Miku. The song constructs its lyrics around a courtroom conceit, the protagonist acts as both defendant and plaintiff in a trial about love, weaving legal terminology through a bright, pop-driven melody. Originally uploaded to Nico Nico Douga, it became one of 40mP's signature works alongside other Vocaloid staples such as トリノコシティ (Torinoko City) and からくりピエロ (Karakuri Pierrot). The music video, still the most-watched version of the song, follows a playful courtroom visual theme that reinforces the lyrical wordplay. In the maimai arcade rhythm game, 恋愛裁判 joined the song list on June 30, 2016 as part of the PiNK PLUS update under the niconico & Vocaloid genre category. It was removed from all regions on July 11, 2019 during a routine catalog refresh, but was reinstated on September 14, 2023, a relatively rare return for a delisted track, signaling its enduring popularity among players. The song's Expert and Master charts were co-designed by two charters, 畳返しとはっぴー and しろいろとはっぴー, who originally pooled their work under the shared alias "合作だよ" (It's a Collaboration) before receiving individual billing from the PRiSM version onward. The Master chart has seen several level adjustments across maimai versions, starting at 10+ in PiNK PLUS and eventually settling at 11+ from UNiVERSE+ onward. Beyond the standard set, a party (宴) chart exists at approximately level 13, bearing the sardonic designer note "リア充向け譜面 ～爆発しろ～" (Chart for people in relationships, explode!), a direct nod to the song's romantic subject matter.