>>532135272
>honestly my reluctance with Manaka is entirely because of my unfamiliarity with her
Have her in idol outfit while doing the VL pose as seen in the expo goods.
https://idolmaster-official.jp/assets/img/va-liv/character/1/image/idol/character.jpg

You could also go with her classic jersey look since that's like what she spent most of her time with (the current jersey avatar was a recent one).
https://idolmaster-official.jp/assets/img/va-liv/character/1/image/trainee/character.jpg
https://shop.asobistore.jp/products/detail/215930-00-00-labo-03