http://www.mangahere.com/manga/hana_no_saku_koro/v01/c001/

The art style is undoubtedly of the one and only Natsume Isaku-sensei. However, I've all of her translated works but have never come across this. The characters look way too cute I can't get them out of my head > <

i can't be sure, but isn't it Tight Rope? it suits the depiction of the characters, lol.

;D