
I'd like some more development on their carriers and the Sentarous relationship with the musician friend, like how did things end like that? I got curious. And what is Touma going to do for life now and a lil more of their interactions, until they admit they're family and Megu's development. Even so it was really cute but lacked depth maybe?

Yes, that too. His friend seems to have manipulated him. But, again, we're not sure since we didn't get the backstory. We were denied of Touma's character arc of getting an honest job and learning how to commit and be responsible in a relationship (romantic with Sentarou and as a parental figure with Megu). A lot of underutilized story potential.
1. Shouji (yakuza guy) is the father. Don't get confused. Touma said Ririko asked about Sentarou's address because she wanted Sentarou to take responsibility as the father. Because out of the 3 guys she slept with, Sentarou is the most reliable.
2. The fact that Shouji is not included in her will is very telling, since Ririko slept with him around the time she slept with our two mcs. It's probably due to the fact that he's involved with the Yakuza (dangerous) and he rejected her.
3. Both Touma and Sentarou said they used condom. Shouji said Ririko always tell him "I love you, I love you" even though he rejected her many times. We can deduce that she may have unprotected sex with the guy she loves (out of passion) unlike with the two mcs.
Review:
The art is beautiful but the story is lacking in substance and depth. It's sad because Touma and Sentarou have a lot of potential as characters. I would have wanted to see Sentarou publish music under his real name, even though it won't be super popular like Papaya, just to reclaim his sense of identity. Their love story is lacking build up and depth too.
Of course, we can all agree, that not doing DNA test is absurd. I thought it's going to be full-on comedy so I kind of let that slide at first, but it didn't.
I've read some of the mangakas works and I think this mangaka is plenty talented but needs a lot of improvement in their writing.