I don't see anything that warrants the see-through tag, but I do see bad angles.

Do her! >=D

I've been waiting for porn of this part. Is it just me or is the fact that Yin is wearing Hei's shirt to bed make this whole picture even hotter?

Artist said:
『盲目の女の子は耳を舐められたらどうなるの？』っと

マジレスすると超気持ちいい
盲目なら普段から耳に意識を集中してるし、いわば常に目隠しプレイ中
鼓膜の奥には粘膜があってそこに続く外耳道もかなり敏感な場所
オマケにインは液体を媒介として観測霊を飛ばすドール
下手すると涎からヘイのエロい欲求が流れ込んでくるかもしれないからヤバい
耳の穴に舌を挿入するとかもう普通に性行為でヤバい

"What happens when a blind girl has her ear licked?"

Feels great to give a serious reply.
If you're blind you'd already have your awareness focused on your ears, like you were always doing some kind of blindfold play.
Beyond the eardrum there's a membrane that connects to the outer ear canal and it's quite sensitive.
On top of that Yin is a doll that uses fluids as a medium for her surveillance specters.
One slip and the saliva would overwhelm her with Hei's lustful thoughts.
Inserting his tongue in her ear or having sex would be even more overwhelming.

The artist's commentary is reminiscent of what Raita wrote regarding Yin in post #120631.