Minamijuujisei Renka by Studio Ryokucha - Adult Sex Game

Ryousuke’s twin imoutos Rena and Rina are geniuses who had already finished all their university courses and now work at the research facility at the southern island nation of Guinberne. He was worried about them, wondering if they would overwork themselves and fall down. So, he decided to transfer to a school in Guinberne, where he was put into the ‘special treatment’ class full of peculiar students.