Yoimachi Meme 
Raincoat Kids [EPUB ebook] 

Dive into the post-apocalyptic water world of Raincoat Kids with constant rain, submerged cities, and a cryptic messaged found at the bottom of a firefly lantern. In this traditionally illustrated word by Yoimachi Meme, follow Minato Aikawa as he takes his younger sistter through the dangerous world to meet with their father. At their side they have self-proclaimed bodyguard Toka and his "ultimate weapon" that seems to be just an umbrella. Will they drown in the murky waters or find their light at the end?