Hashitanai Shimaidesuga, Shitsuke Ketemoraemasu Ka? Shishi Ma Shirube Shi Ha Fukuju No Kubiwa Nite Shimai to Chigiru (Fantasia Bunko) [Light Novel]

[Machine Translation] The story is about a boy, Kusabu Kuro, who became a beast mage candidate in order to reunite with his sisters, who were separated after being transformed into a phantasmal beast. The best way to get the best out of the game is to make a contract with the sisters and aim for the top of the school in order to win your freedom. The first thing to do is to get a good look at the newest version of the game. The sisters are not allowed to wear underwear, and they are also not allowed to walk around without being exposed. I'll do my best for Master... The more he disciplines them, the stronger they become. The more you discipline them, the stronger they become in this school beast fantasy!

「私たちはどうしようもなく“はしたない獣”なの」幻獣化し離ればなれになった姉妹と再会するため、獣魔導士候補生となった少年・昏部玖郎。「柊遊奈、柊利亜、汝らは我が獣となるか」「―はい」彼女たちと主従の契約を結び、自由を勝ち取るため目指すは学園の頂点。「じゃあ今から外へ出かけるぞ。四足歩行でな」強さを求める姉妹の願いを叶えるべく玖郎は、下着着用禁止に露出散歩と、彼女たちに“はしたない”躾けをすることに!?「ご主人様のために頑張るから...後でご褒美お願いね?」躾けるほどに強くなる学園ビーストファンタジー!!