[Sevengar] Shokuba no Namaiki Kouhai-chan, Cli Choukyou ni yori Tachiba o Wakarasareru. [EroTranslations]

Kanagi Erina, the office's teasing heartbreaker, challenges her rumored playboy senpai to a 'sex battle' to put him in his place — and instead ends up gasping and cumming endlessly under his relentless clit play. Her defeat kicks off a strict training regimen: secret restraints strapped beneath her work skirt all day, a groveling costume performance where she offers herself as his 'personal fuck hole,' and a final reward where a toothbrush against her most sensitive spot leaves her squirting and thanking him mid-climax. The once-impertinent junior learns her place fast, and the handsome cock is declared the undisputed winner of the sex battle.