ミナト（青木柚）が元カノ・関田（芋生悠）と会っているところを目撃し、浮気ではないかと動揺する鮎美（夏帆）。しかし全く悪気のない様子のミナトは、鮎美が待つ家に関田を連れて帰ってきた挙句、一緒に飲もうと提案してくる始末。しかもミナトは、鮎美が料理を作ってミナトの帰りを待つ中、スーパーでお惣菜を買って帰ってくるなどマイペースを崩す気配もなく、鮎美は悶々としてしまう。
一方、ミナトに鮎美を託すと決めたもののいまだ未練を捨てきれない勝男（竹内涼真）のもとを、地元の大分から兄・鷹広（塚本高史）が訪ねてくる。そこで勝男は、いつでも自分より優秀で一人で何でも解決できる人だと思っていた鷹広の、ある苦悩に触れることに。そして鷹広を励ますため、あることを思い付く。しかし、勝男のその思い付きに鮎美も巻き込まれていき…。
Ayumi is shaken after seeing Minato with his ex-girlfriend Sekita and begins to suspect he may be cheating. However, Minato shows no sense of guilt—he even brings Sekita back to their home and casually suggests they all drink together. His carefree attitude continues to frustrate Ayumi, especially as he disregards her efforts, such as buying prepared food instead of appreciating the meals she cooks for him.
Meanwhile, Katsuo, who has resolved to leave Ayumi in Minato’s hands but still struggles to move on, is visited by his older brother Takahiro from Oita. Through their reunion, Katsuo learns of an unexpected hardship his seemingly perfect brother has been facing. Determined to encourage him, Katsuo comes up with an idea—but it soon draws Ayumi into the situation as well.
