i like both too much to have a definitive preference, and most of my closest friends are no switch/have a heavy preference for mksh/shmk. i am normally the "true neutral" out of my mutuals, i'm genuinely open to most scenarios/interpretations (within reason obviously, i may seem like a gooner but i like analysis/plot with my porn).

some aus in my mind may lean more top/bottom heavy depending on how i perceive their personalities and experiences in that universe (vanpro is one of these aus i view them as leaning towards shumika, ougonten/dragonfruit being mikashu, there's more examples i can provide too)

in canon, i see shu being more comfortable topping at first but gets more comfortable and vulnerable to let mika top (and actually WANT to switch more). i think it's overly emotional for him too, i have a hard time trying to imagine shu as someone who bottoms just out of the gate for their first time, considering how strict he has been with himself in the past over what goes into his body. i have this headcanon that may be unpopular, but i think shu was neglected/abused more than what his stories give us context of. that abuse, in my headcanon, had a HUGE part in his deep infatuation and obsession with nazuna in his first year, and his fall from grace after valkyrie's defeat + his dissociative states. that's why, i don't think it's a stretch because of his trauma, his prudishness, and his desire for someone close, but his overwhelming desire for control, that he wants to top for at least their first time. he gets more comfortable as time goes on with relinquishing power and, per his request to mika, letting mika control him, rather than the usual puppetmaster controlling his puppet. although.. mika does take initiative Quite A Bit me thinks. i just think he does MOSTLY what shu would ask, unless he was angry at him or too impatient. i like angry mika a lot when he actually expresses his anger/frustration towards shu. besides we already got confirmation in the story theyre loud and shu's apartment has thin walls.. heh. heheh. i also interpret different stories as shmk / mksh-coded (ie hoshi no meidou being mksh coded)

i have been a fan of mikashu more recently because of my beloved echo chambers groupchat (shoutout to my goats) but i used to be shumika only when i first started producing valkyrie (and hadn't read as many stories). now i am a genuine middle of the road person, i love both and i will interact with both/write both dynamics. different aus mean different dynamics i like to experiment with and analyze their behavior. i wish to observe them in jars and shake them around

regular couple yaoi couple yuri couple i see no difference. love is love