On her way to school one morning, a boy from another school gives Himeno a love letter. The sudden turn of events has Himeno bewildered, and behind her bewilderment likes a traumatic memory from her childhood. What happened in Himeno's past? Himeno and Nozomi have come to Kyoko's house for a study meeting. As they're working, something strange happens...
That way, even if you forget the formula,
 you can find the answer.
يمكنك حينها إيجاد الإجابة 
.حتّى لو نسيتِ المعادلة
Selbst wenn du dann die Formel vergisst,
Así, aunque olvides la fórmula,
puedes encontrar la respuesta.
Así, aunque olvides la fórmula,
puedes encontrar la respuesta.
così, anche se scordi la formula,
puoi comunque trovare la risposta.
Assim, mesmo que esqueça a fórmula, 
você vai chegar na resposta.
Даже если забудешь формулу, 
то всё равно сможешь решить задачу.