My sister-in-law Yuri, who had returned home after giving birth, was worried about her husband Kazuki being alone and decided to check up on him. Kazuki, finding Yuri's cute smile endearing, happily welcomed her back. However, unbeknownst to Kazuki, Yuri's true intention was to use him to satisfy her unfulfilled desires since their marriage wasn't going well. As they relaxed together in the hot springs, unaware of each other's intentions, Yuri stealthily approached Kazuki...