Kakeru enters the soccer club as a provisional member, just as the letter says. When the topic of lunches comes up after practice, Kakeru jokingly asks Naho to make lunch for him as well. Naho finds herself bewildered by his words, but feels pushed to act by the letter from herself 10 years in the future, which tells Naho that she wishes she had made lunch for Kakeru.
A letter can't change a 
person's personality so easily.
.لا يمكن أن تغيّر رسالة شخصيّة أحدٍ ما بسهولة
Man kann sich nicht einfach
durch einen Brief verändern.
Una carta no hará
que mi personalidad cambie fácilmente.
Una carta no conseguirá que mi 
personalidad cambie fácilmente.
Ce n’est pas elle 
qui va tout changer.
Non basta una semplice lettera
 a cambiare la propria personalità.
E impossível mudar a personalidade
 de uma pessoa tão facilmente,
Письмо не может в одночасье 
изменить человека.