Naho can't give her Valentine's Day chocolate to Kakeru. Ever since what happened on New Year's Eve, Kakeru keeps putting distance between Naho and himself. But, through all the hardships, Naho refuses to give up and fully intends to tell Kakeru how she feels. And so, the time comes for everyone to face the fateful day outlined in the letters from the past, "Kakeru's Final Day."
The letters would cease to exist the moment 
the "Kakeru doesn't die" future comes to be.
لن تكون الرسائل موجودة لحظة وقوع
 ".مستقبل "كاكيرو لا يموت
Sobald eine Zukunft entsteht,
in der Kakeru nicht stirbt,
En un futuro donde Kakeru
no está muerto,
En un futuro donde Kakeru
no está muerto,
En créant ce futur 
où Kakeru ne meurt pas,
Nel momento in cui il futuro cambierà in uno 
in cui Kakeru non è morto, le lettere spariranno.
No momento em que um futuro no qual
 o Kakeru está vivo passar a existir,
Письма перестанут существовать,
когда начнётся будущее, где Какэру не умер.