Nekojiru Udon

Everything would have been perfect in the best of possible worlds if Death had not decided to come and pick up the hero's little sister. Despite being a kitten, he does not intend to let himself be carried away by this sinister character. Between fascination for the absurd, and immoderate taste for a sweet wickedness, Nekojiru stages Nyato and Nyata, who under their airs of cute little kittens, will set fire to the whole planet.

(Source: IMHO, translated)

Note:
-Originally serialized in Monthly Manga Garo for 31 chapters, starting with the 1990-06 and ending with the 1995-10 issue.
-Incomplete 2-volume tankoubon (23 chs) published by Seirindo in 1992 and 1995.
-Complete 3-volume tankoubon published by Bungeishunjuu in 1998 and 1999. This tankoubon collects all chapters with the exception of "□nugoroshi no Maki" (□ぬごろしの巻). It additionally includes 3 newly drawn chapters (one in each volume) as well as the One Shot "Nyango-tan" (にゃんごたん) by Nekojiru-y, originally published in COMIC Gon No. 3 (November 1998).
-The tankoubon releases change the order of the chapters. The credits on this entry are according to this ordering.
-The chapter "Neko Saiban no Maki" (ねこさいばんの巻) was published in English as "kitty court drama" in the anthology "Sake Jock" by Fantagraphics Books.