I'm guessing at the end of the first volume Omi managed to synthesize a semen compound and "inserted" it into various women and told them it was Junpei's doing just for kicks, which, arguably is much more fantastic then saying, "Hiya! I impregnated you with synthetic semen. Too bad you weren't woken up by the "real thing" like me Hurr hurr hurr".
Primary:
Sky
Slate
Blackcurrant
Watermelon
Strawberry
Orange
Banana
Apple
Emerald
Chocolate
Marble
Secondary:
Sky
Slate
Blackcurrant
Watermelon
Strawberry
Orange
Banana
Apple
Emerald
Chocolate
Marble
Pattern:
Blank
Waves
Squares
Notes
Sharp
Wood
Rockface
Leather
Honey
Vertical
Triangles