Heaven's Lost Property (2009)

S2E4 Mortal Combat! Hot Spring Snowball Fight at 1.4° Below

As winter settles over the city, Astraea remains no closer to finishing her mission to eliminate Tomoki. Mikako drags her into yet another cruel game, this time orchestrating a mock battle between the school's boys and girls. She names Tomoki general of the boys while taking command of the girls herself. To lure him in, she offers a tempting prize: the winning side can do anything they want to the losers. Meanwhile, Nymph still longs for a new master, and Astraea finds herself torn when she cannot bring herself to kill Tomoki, haunted by his question of whether her actions are truly her own choice.