>>29807174Because that's what Shoko wanted and Serena is literally Shoko's self-insert
After a few years, Shoko realized that she wasn't satisfied with the "Satoshi and Shoko-tan love drama" script, so she convinced the staff that it was finally time to introduce Satoshi's wife.
Of course she needed to be perfect, just like Shoko. A kawaii and girly girl who loves to dance, cook and sing, unlike all those previous tomboyish "girls".
And that's how Shoko achieved her dream of winning Satoshi's heart
and dick.