Just Like Mona Lisa 03

Why does Hinase feel so uncomfortable with both choosing a gender and exploring romance? Their friends are growing up without them, and Hinase's nostalgia for a simple childhood creates friction. After Hinase awakes from a brush with death to an ever-changing present, Shiori drifts away, blaming himself for their misfortune. Ritsu hopes to uncover the source of Hinase's anxiety--but that's a struggle Hinase will have to overcome on their own.

What is the connection between gender and attraction?