Nise no Chigiri二世の契り ; 二世之约 ; Lời thề nguyền ; Marriage Vows ; Schwur der Zeit (German) ; Second Generation Promises

Mana is an ordinary high-school student who somehow travels through time to the Sengoku Jidai (the Warring States Period) and encounters Uesugi Masatora, one of the generals. He decides to protect her, while his rival Takeda Shingen targets her. With Mana knowing the outcome of this war, will she change the future?