RYU, whose father has remarried, becomes a sister-in-law with Erica, who is close to her age. The two set off on a trip to deepen their sisters' friendship, but from the beginning, Erica wanted RYU's body. Erika, who saw RYU's body at the hot spring, could not suppress her desire, and took RYU's lips while taking a walk outdoors and asked for his body. Even RYU, who resists, gets fucked as he pleases. RYU is still reluctant to be of the same sex, but without suppressing his rising feelings, the two of them seek each other out in the guest room at night.