why somehow this manga remind me of the origin of Bowsette? <especially the first panel>
Because it perfectly matches the sequence of events panel-for-panel, outside of the use of any super crown. The first comment is even saying that it's a copy of the original Bowsette 4koma.
Now that I look back on this, wouldn't this technically count as bisexual since she shows interest in both? She got turned down by Rinnosuke sure, but nothing implies the rejection turned her gay.