Born as the youngest of three brothers, Kenta was seen by his mother Yui as a quiet and submissive child who didn't assert himself much... However, when both of his older brothers moved out and started living alone, and their father went on a business trip, leaving just Yui and Kenta in the house together, she felt a sense of loss and emptiness. Seeing her mother's sadness, Kenta couldn't help but feel lonely and regretful that he hadn't been able to experience the love and affection she had given to his siblings before them. Determined to reclaim what he believed was rightfully his, Kenta decided to take matters into his own hands and shower his mother with love and attention like never before.

3人兄弟の末っ子として生まれてきた健太。母親・清香からすると自己主張をしない大人しい子という印象だったのだが…。ある年の春、兄のふたりが1人暮らしを始め、父親は単身赴任と慌ただしく生活が変化して健太と清香の母子2人暮らしが始まった。賑やかな家が急に静かになり喪失感を感じる清香…。そんな母の様子を見て、健太は寂しさと悔しさを感じ、今まで独占できなかった母親の愛情を取り戻そうとして…。