Yakumo Rio

She is the granddaughter of the boss of the Yagumo-gumi.
She is a nurse.

She previously had a difficult experience when she was caught up in a power struggle between the gangs, but she has renewed her resolve and achieved her goal of becoming a nurse.

She currently works at a hospital near the Otobe-gumi, and lives alone as it is far from her parents' home.

She is engaged to Amamiya Seiichi, the young boss of the Yagumo-gumi, whom she has admired for a long time, and is currently making various preparations for her wedding. The previous and previous previous bosses of the Yagumo-gumi and Otobe-gumi were good friends, so Rio and Shizuka have been meeting since they were young.

As they are in similar positions, they have been talking to each other since they were young, and they treat each other like a second sister.

Now they live nearby, so they often visit Shizuka's house.