I just got my hands on the yuri momcest collection My Sweet Home and the Tae-chan side chapter was awesome. Sadly I can't actually read it but just from looking at it it appears that Noko is in the same class as Kuyou. One day she see's Kuyou with a hickey on her neck and asks about it, with Kuyou about to show her pics on her phone of how she got it but Ito calls Kuyou away for a bit. Kuyou leaves her phone and Noko decides to look through it and sees selfies Kuyou took when she was having sex with manami. This makes Noko wonder if this was what her mom and Ai have always been doing together. It looks to me like she decides to confront Ai about it because there is one panel where it shows Ai getting handsy with Noko's body. Sometime after that it appears Noko finally confronts her mother about it when they are alone at last(guess Ai lives with them now). Pretty sure Noko and Ai decide they had more than mother/daughter feelings for each other because things escalate VERY quickly. Sometime later Ai gets home and finds Ui and Noko naked under the kotatsu having sex. Judging from Ai's reaction, Noko's proud smile and Ui's we-got-caught :P reaction I think they are going to become a yuri 3 way family by the time we see them next in the main story.
Volume 1 of the manga is going to go on sale soon and Melon Books is giving out some sweet bonus' for it's release. One bonus is a tapestry that depicts one of the side blurbs in the borders of the manga, when Manami and Kuyou went out on there first date. It shows Manami and Kuyou making out at the aquarium. Another bonus has a color card that shows Manami and Rise in the bath, and another card that shows a new side story that appears to show Manami and Kuyou on a double date with Ito and Chika to a pool or the beach.