Thanks Winnie & Tomo, I have a better understanding of how she works now. Don't worry about IsaVulpes re-structuring your posts, I put him on ignore a long time ago for obvious reasons.
I don't see anything she has being nearly as bad as SDE Cat Heads though...
Put into more simple terms, I would say her biggest weakness is good vertical mobility.
Valentine is the biggest culprit but Squigly can be a pain too as you are the one who wants to rush Squigly down in that matchup.
MK shadows only hit so high, basically anything above MK shadow height is Fukua's dead zone, that is where you want to be most often when playing against her. Once you are close, shadows become a very risky option for her as you can predict/even react super close and counterhit her in startup.
She is going to want to stay in the air, so from range, take this time to run forward if you are on the ground and block fireballs, obviously she cannot shadow from the air. If she whiffs a fireball run underneath her to avoid j.MK/j.MK and then pressure her on landing.
If she is on the ground, great, get high in the air as fast as possible if you expect shadow and move in. If you preemptively get into the air though, she will probably tag you with a shadow on the way down, you don't want that to happen.
If she is pressuring you, watch her tendencies after 2HP. You can challenge MK and HK shadow straight up and counterhit into a huge punish. You jump forward out of LK shadow or a delayed fireball/drill. If she likes to do fireball WITHOUT a kara, you are +, so go nuts. If she does it with a 5HK kara, you can almost always jump forward. If she likes to LK drill, you are also + there, but less so, so be aware of reversals, this is a good place to try those crossups for characters with fast ones.
When she is pressuring you with j.HK and j.HK xx LP fireball.. yeah that's when to be scared. Do NOT stop crouching, if you do, you can be fuzzied and you don't want that. She has no IOH and no overhead out of j.HK so her options are much more limited. The fireball will only cross up if the j.HK makes contact, so try to be aware of what she is doing, pushblock appropriately and try again. If she does the j.HK xx fireball and it whiffs, then you can punish, if not with a counterhit, then at least with pressure.