Kimi no Naka Ni
Oneshot Touma(♂) and Rikka(♀) have both always been in love with their childhood friend Aki(♂). Knowing that Aki will never choose him, Touma puts on a brave face when Aki tells him that he's thinking of asking out Rikka during their high school years. The relationship progresses smoothly and Touma watches sadly from the sidelines as Aki and Rikka get married, unable to get over his lifelong love. One night, he suddenly gets a call from Aki informing him that Rikka was killed in an accident, and Touma rushes over to find a distraught Aki totally incapable of taking care of himself. In a desperate move to stop Aki from crying, Touma puts on some of Rikka's old perfume and holds Aki close, telling him that she's still here and that she loves him. The situation quickly spirals out of control, and while Aki is able to get back on his feet, he becomes delusional and stops seeing Touma for who he really is...
December Rain