You really need to get a knit for that fit on those sleeves unless you put an invisible zipper in from the cuff of the top sleeve or from the elbow down.as far as the romper there are tons of "how to make a gathered skirt tutorial" on youtube, but even with that for an anime poofy I would atleast buy a low loft petticoat.
Anime USA 2015...Halloween!
Steven Universe- Rose Quartz Gown version
Evangelion- Asuka Langley Soryu Yellow Sunddress
Magic Night Raye Earth- Ferio Yellow Shirt Version
Yuri Kuma Arashi- Kureha Bear Form
Yuri Kuma Arashi- Kureha OR Lulu School Outfit
Artist's Alley Hopeful....We'll See
Awesome Con 2016
Deadpool/X-men Comics- Siryn...not sure which version yet...
DC Comics- Raven Either Teen Titans or Original Comics version....