As the second eldest son in a big, poverty-stricken family, Kouno Kazuomi has to look after his younger siblings. At school, he's the low-energy-consuming cool boy. He was only devoted to his family before, but his senior of 2 years, Makise Koutarou, invites him and now he's part of the Gardening Association. Despite being bewildered by Koutarou's excessive physical contact and friendliness, Kazuomi slowly opens up to him; the first senior he got along with. However, he witnesses Koutarou, #1 popular guy in school, in a scene showing his free-spirited nature regarding relationships, and Kazuomi's heart trembles in pain. A riajuu senpai that can't stay long in a relationship and an innocent kouhai who doesn't know love - their sweet, melting youth begins. The story of Kazuomi's brother, Takaomi and his rival at the time - Kusuhara's - "love between businessmen under one roof" is also included! 貧乏大家族の次男として弟たちの面倒をみている河野和臣は、学校では人と関わらずに過ごす省エネ系クール男子。家族のことだけに心血を注ぐ彼だったが、2コ上の先輩・牧瀬洸太郎に押し切られ、突如「園芸同好会」に入ることに！スキンシップ過多な洸太郎の距離感に戸惑いつつも、初めてできた先輩に少しずつ心を開いていく和臣。だが、学校一モテる洸太郎の性に奔放な一面を目撃してしまい、和臣の心は痛みに震え――…。