Hinako

Hinako (ひなこ) is one of Rin's younger sisters.

Information
Hinako is the daughter of Wataru and Kagura Inou. She may also be one of the twelve girls who admire Wataru as a older brother and went with him.

Summer Radish Vacation!! 2
In one possible scene of Rin's first appearance, her name is among those Tomaru uses when he tries to guess Rin's name.