>>2758004You're supposed to take one of those R Kasumi bromides and combine them with other bromides to max out the level.
Ideally you'd combine identical bromides since you get more exp that way and it's also the reason why they offer those R bromides in packs of 33. Combining all of them would give you a maxed level bromide.
Outfits tab > Cheering board > Upgrade Bromides
Then combine your dupes until level 5. Once at level 5 you can rarity up them to turn R's into SR's, SR's into SSRs, etc.
Through this long process of grind one can turn their SSR level bromides into SSR+ level which reduces the cost of equipping them and would allow someone to equip 3 bromides on a girl.
Needing all those SSR level bromides to use as fodder, likely non dupe fodder meaning you'd need even more, is why it's pretty much a feature for those that have the stones to spend on bromide gachas and prime whale bait.
As for what Bromides actually do for you just think of them as another skill to equip just like you would on the accessory slot menu.
The difference here is that you can double up on bromide skills and they just work, whereas skills you slot into accessories and skills on the swimsuits do not stack if they have identical names.
Cheering board type has to match the slot type as well so no mixing and matching STM bromides with TEC/POW.
Lastly there are two types of bromides. Girl specific and general use bromides.
General use are just that. Anyone can equip them with no restrictions.
If a girl equips a bromide belonging to someone else they'll only get a % of the skills effect unless the two girls have raised their closeness level in the owner room. iirc it's closeness level 50 between two girls to get 100%. Can't equip someone else's as your main frame, only in the slots.
Dont confuse girl specific bromides with bromides that have the girl's chibi on them either. Girl specific have the girl's icon in the bottom right as well as their name as part of the bromides name.