Changes of Heart, Volume 6 (Changes of Heart #20-23)

Childhood friends, Hijiri and Koyori are now officially together. They moved in together, got through their first big fight, and strengthened the bond between them. While they're busy with work and taking a hot spring trip on Hijiri's first birthday as a couple, Koyori's ex-boyfriend makes the announcement that he's getting married! Which gets the couple thinking about their future.