I feel like I need to explain a couple things. Other than the obvious timeskip (ten years from now), after 3 years of marriage, Tetsu and Kei adopted 2 children; 2 boys, twins (Akira and Jun (aka - Juni)) in 2018 at 2 years old. Three years later, they adopted 1 girl (Megumi) at 1 year old. They are currently 15 and 10 respectively.
Akira, Jun, and Megumi call Tetsu and Kei 'dad,' 'daddy,' or 'papa.' It really just depends on what comes to mind first. KT never really thought to just go by one or the other, and they found it amusing to hear themselves be called whichever name. They loved it.
Keiji and Koutaro also adopted twin sons (Chika and Kaoru) in 2018, also at the age of 2. They are also 15 years old.
In quite a few of my stories, I've written BAKT* not only as a squad, but closer than that, like family. Pairings remain the same, but KT* will call BA* 'brother,' and vice versa.
*BAKT = Bokuto Koutaro, Akaashi Keiji, Kuroo Tetsuro, Tsukishima Kei
BA = BokuAka (pair)
KT = KurooTsuki (pair)

