Characters
Generally speaking the community wants the characters that are missing/have been substituted. Namely the 'lolis'. These are of course for various reason. Some are 'upset' about the missing strategy options. While others want the characters themselves. While we all know the reason such thing is an issue for Nutaku. My suggestion is to use the slots to give us the promised/mentioned Nutaku exclusive characters. While DMM/JP would have these lolis. Nutaku/EN would have other characters. The stats and skills would be the same. Satisfying those who want their strategic options. This could work until such time as we are able to receive these kinds of characters, and after that no more exclusives for either side. As they would not be needed. Besides this interest seems to be on how we would get any of the sapphire rarity units, or the few collaboration units.
Story
The story in general seems popular amongst those who care about the lore. There are multiple request for the main story to continue with the release of the desert maps. Besides the main story maps or 'skipped' events such as 'threat of the dark knights', it is character stories that are most desired. Specifically the female character stories that exist in the all-ages version of MWA on DMM, as well as the character books and manga who some on the community wish to be translated at some point.
Events
Star Rush is the most popular amongst the community, due to the factor of their generally being more of a challenge. In addition to being able to farm normally for other materials while getting a perfect event unit. Gold Rush and Subjugation events have been requested by some, as well as reprint events that will obviously come with time.
This is just a very brief summary of some of the repeated things I've noticed mentioned. Though this thread seems to have become a 'what I want now from the JP version instead of what I have enjoyed from what currently exist' thread.