The senpai of Masato Hijirikawa and Ren Jinguuji.
He's a highly reactive and moody person, right into tsundere territory. He does however have a strong sense of duty. Ranmaru considers himself a rocker through and through and has his own ideals about what 'being a rocker' actually means and is actually fairly misogynistic in nature, refusing to work with Haruka because he wouldn't sing a song written by a girl. He stated that he didn't think anything but rock could speak to him after hearing ST☆RISH's song Maji LOVE 2000%.
