Shinju

Shinju derives from two Japanese characters: mind & centre, and means "double suicide" committed by two or more people bound by love.
In Japanese theatre and literary tradition, double suicides are the simultaneous suicides of two lovers whose personal feelings or love for one another are at odds with social conventions or familial obligations. Shinju for them is their way out, hoping for a content life together in the next world.
(Explanation is based on Mitsuya Mori's definitions)