Serva Fes no Genkou Sagyou de Tamatta Master o Musashi-chan to Okkii ga Nuite Kureru Hon.

Alternative

A book in which Musashi-chan and Batty will help Master get rid of the cum he accumulated during ServantFes | サバフェスの原稿作業で溜まったマスターを武蔵ちゃんとおっきーが抜いてくれる本。