Natsuhane and Hiroshi have been close mother and son since forever.
The family's annual tradition is to go on a hot spring trip together.
This year, the father is busy, so Natsuhane and Hiroshi are going on the hot spring trip just the two of them.
A delicate relationship between mother and son surfaces in the absence of the father.
Natsuhane, who has been estranged from her husband. And Natsuhane and Hiroshi realize they have been aware of each other as members of the opposite sex.
At first, Natsuhane rejects their relationship due to societal pressure, but ultimately accepts it and they greedily seek each other…
