Scent

Shikaku doesn't need a calendar to mark the change of seasons, he can tell it by scent alone.

Winter smells like cooking – hearty hot pots like nabeyaki udo, tonjiru and oden.

It doesn't matter if flowers are blooming yet, he can tell when she switches her perfume to that light, sweet floral fragrance that it's now spring.

Summer is the time when the whole house smells scrubbed fresh and clean, breezes billow through open windows and at night there are sun-dried linens on the bed.

Likewise he knows it's autumn because Yoshino smells like warmth and vanilla and home.