My Youth Romantic Comedy Is Wrong, As I Expected @ comic, Vol. 13 (manga) — Wataru Watari

The start of winter brings trying times for Hachiman. There's Iroha's selfish request for a “date,” his little sis Komachi's insistence on an overcrowded New Year's shrine visit, and Yukino's birthday on the horizon. Just as Hachiman and Yui are out shopping for the right gift, a chance meeting with Yukino's sister, Haruno, lands them in a social minefield -- one fraught with awkward family ties and a history everyone is reluctant to get in to.