One of my favorite brands is Nile Perch, they make super cute clothes in fairy kei style. Their clothes are more casual than the lolita style so its perfect for a more casual style. Their look is very retro and sweet. I went to their shop when I was in Harajuku and it looks so adorable, I wish my bedroom looked like this!
Their aesthetic is very childish and soft. I think it really suits larme and fairy kei. Sadly their clothes can be quite expensive, I would recommend finding them second hand on closet child or japanese auction sites!
All their items are so perfectly adorable, be sure to check out their shop there is so much cute things there. A lot of their items work well with sweet lolita also.