24-ku no Hanako-san

A unique space has appeared in Tokyo, commonly known as the "24th Wards." Common sense and physical laws do not apply there, so it was deemed a danger zone and was promptly closed. However, when Kosuke infiltrates the 24th ward in search of his missing younger brother, he meets a mysterious girl named Hanako-san. At first, Kosuke rejects the elusive Hanako, but is gradually attracted to the 24th Ward... and Hanako! Delve into the mystery surrounding the 24th ward in this boy meets girl fantasy!

(Source: Akita Shoten, translated)