Suiren

Track 1 of Kakashi runs 4:36 on Wikipedia and 4:33 on a Japanese listing. Wikipedia credits Shimizu as writer; a Japanese listing credits lyrics to Aki Ikuta with Shimizu singing, which we could not verify. By the track-number credits, Hijikata plays guitar, Koji Yamaguchi French horn and Mitsuru Orikasa cello, with Yamaki and Watanabe. Resident Advisor describes an opener of jaunty jazz pop layers building in intensity and spilling into the title track; Record Collector hears ska-like rhythms; Spectrum Culture hears a sampled loop that suggests an electronic meow, then Shimizu on tenor saxophone moving between a martial rhythm, a brass sample of a classical melody and vocals.

We found no interview about its meaning, no covers or samples, and it appears in none of the setlist.fm setlists we read from the 2018 and 2025 tours.