after the explusion from her peer group i noticed the author seem to bring these into the table
- mari become lazy (at school) and listless and unable to concentrate
- mari now friendless and yet still avoid attention of boys who want to be friend with her
- yori still not speaking to mari
- momoka happily took over her group as the alpha female and not under the shadow of (the more beautiful) mari
- hiroki break up with momoka didnt faze momoka at all, seems like it is what momoka wants
- mari is not concerned with her day to day routine like becoming more slovenly and lazy at home too, making her mother question her.
- even friendless at school, mari still top dog in beauty, as shown on how everyone seem to greet mari or silently admire her at school.
i see that its the old 'isao' taking over and becoming realized in mari's life (theories aside, i bet even the author dont yet know what caused the switch or if any switch is happening at all)..
this manga and the author's direction is going purely toward a 'what-if' situation if some male suddenly transfered into girl, along with the complexities and hilarious thing that happened (like menstruation, boys, girls etc)
the hiroki forcing himself to mari should be a culmination of what the author want readers to feel if a male inside girl's body suddenly get kissed by a boy.. what should he feels given that all hormonal he(she) got now is female..