The term "sakuga hōkai" (animation collapse) is currently trending on Twitter. The term refers to poor animation, particularly when productions seem unable to control quality and the level of animation deteriorates. The term began trending on Twitter as a fan reaction to the second episode of the My Sister, My Writer television anime, which debuted on Wednesday night.

Fans took to Twitter to decry the poor animation in the episode. The tweet above, for example, compares character depictions from the first and second episodes of the series.

Naturally, fans began to wonder about the disparity in the quality of animation between the episodes. A few Twitter users responded with what they believe is the cause after seeing the credits for the anime's second episode. The animation production company Buyu is credited with the key animation, in-between animation, in-between check, and finish animation for the episode. The company was initially only credited with in-between animation and finish animation for the first episode. Multiple individual staffers are often credited with key animation rather than single companies.

Online commenters pointed out that Buyu was founded as a finishing studio and later established production, animation, and photography departments. Twitter users reported that the company's Wikipedia page states that the animation and photography departments have since been dissolved, and the company's current focus is filling in-between and finish animation requests from other companies.

Some fans are speculating that a major part of the animation process for the second episode may have actually been outsourced overseas.

The anime adapts Seiji Ebisu 's Ore ga Suki nano wa Imōto dakedo Imōto ja nai ( The One I Love is My Little Sister But She's Not a Little Sister ) light novel series. The anime's planned early streaming of the first episode was cancelled "due to production issues." The series premiered on television in Japan on October 10, and Crunchyroll is streaming the series as it airs.

In a similar case of questionable animation, fans criticized DYNAMIC CHORD last November.

[Via Nijimen]