From Attractive Fascinante:

After his parents passed away, Aizawa Kyouichirou, a middle third year high schooler, rented out the 6LDK apartment in the form of room sharing as suggested by his guardian, Yagi Akira. The occupants were Rio Forest - a foreign college student, Mutou Keigo – a National Literature college student, Kawakami Shinji – a top host and Tachibana Jinpei – a workaholic. After they started to live with each other, they learned how to love and care for each other.