I'm not sure if I should tag Shinji here (or Kaji in this post's parent post), since I'm not sure the label mentioning a character's cum counts as including a character.

attomachine2 said in comment #2611625:

I'm not sure if I should tag Shinji here (or Kaji in this post's parent post), since I'm not sure the label mentioning a character's cum counts as including a character.

You should have written "Shinji's semen" on the label instead for appropriate alliteration. Would have paired perfectly with "Kaji's cum".

attomachine2 said in comment #2611625:

I'm not sure the label mentioning a character's cum counts as including a character.

The implication that the semen came from Shinji is not enough for him to be added in the tags, so you don't have to tag him here.