Kanna is a 4 star harpoonist despite being in her early 20s. In other words, shes a prodigy who has killed over 400 sea monsters, only 1 harpoonist having more stars in the city she comes from.
Leviathan
The world is submerged, and sea monsters rule the earth. Will Bota and his family ever make it to safety and escape this aquatic hell? ...And who in the world is Kana?!
