Based on @koyuki-tan‘s “Peace Sign.”
– He is ecstatic for a cousin.
– If, however, Isamu gets more attention than him, Masanori might feel a little insecure and need reassurance from h s parents.
– He loves playing with baby Isamu. Mostly this involves “drawing” on Isamu’s face.
– Eventually, he likes Isamu so much he asks his parents to adopt him AND give him another baby sibling. This causes existential crises for both Uihai and Koharyo.
– They’re eventually known as the devil twins who will give their loving parents headaches with mischief, but they wouldn’t trade them for anything. ❤