Orokamono (2019)

Since the death of their parents, Yoko and Kenji have been inseparable. One night, Yoko witnesses her brother dating an unknown woman. This, of course, wouldn't be a problem - if Kenji was not already engaged. Yoko confronts the woman named Misa, asking her to end the affair. But pretty soon she starts to realize that Misa might be a better match for Kenji than his current fiancée.