Yellow Elephant

Married couple Aiko Tsumari and Ayumu Muko live a happy and peaceful life. Aiko is bit naive, while Ayumu works as a not so popular novelist. One day, a letter arrives for Ayumu. Because of this letter, the couple become estranged.
(Source: AsianWiki)
~~ Adapted from the novel "Kiiroi Zou" (きいろいゾウ) by Nishi Kanako (西加奈子).