its bout character design, its not bout animating costs. one can simplify the drawing while retaining the design. but this one doesnt. it somehow modify it heavily.
try look at Kurenai the TV series, then somehow they retaining the character design in the OVA.

i know u like the show, but then u tend to try (in every way) to lick off their dirt to make their shoes shine.

frankly, this is not ur 1st post that make me wanna do tat. i observe how u posted n most how u post ur opinion, either u lick or u spit. maybe the word i use is a lil harsh. yet tryin to praise with BS or judge the book by its cover is a bit too much.

i wanna throw in Yokazura Quartet (both TV n OVA has different character design) in to the comparison, but i never read the manga b4, so i cant throw in to judge the character design.