Sirens have the power to control the sea, and they have fatal beauty temptations. However, they also have a fatal flaw. The memory of the Siren is very short, and he will forget everything within two days, so they use their own scales as pens, and every word they write down will be deeply engraved in the Siren's mind. Memories can be turned into books, which are called "Siren's Diary".
Intention: Don't forget easily