Masaki Sonoue is a video content creator who produces "Mayonaka Punch." Dedicates her life to video production, taking charge of planning, filming, and editing. Her strong-willed nature is both a strength and a flaw.

She was previously active as "Masakichi" in "Harikiri Sisters", until she was kicked out of the group and fired due to a fight between her and her colleagues Kikka and Otomi.