Monogatari Series: Family Season

Koyomi Araragi and Hitagi Senjougahara are finally married. Shinobu Oshino and Suruga Kanbaru accompany the couple on their eccentric honeymoon, and the itinerary includes an investigation into a strange phenomenon. Koyomi has a plan related to Hitagi and Shinobu? These are the modern-day oddities! Oddities! Oddities!

(Source: Kodansha, translated)