If someone kisses you on the lips every single day... is it romantic?
Or is it just... a habit?
You see, for middle-schooler Shou-chan, getting aggressively kissed by his childhood friend, Mana-chan, has become completely normal. His brain has habituated to it. It’s like the smell of your own house, or the feeling of your clothes on your skin. Your brain just deletes the sensory overload to keep you sane.
If Shou eventually falls in love with someone else, does the habit die? Or... does the habit fight back? Will Shou try to do something different in his new romantic pursuit to win that person's affection? Will he tell them, "no, we don't kiss because we are in love, not friends"?
If Mana-chan is just copying her mother’s grand displays of affection, what happens when those displays are rejected? What happens when Shou now wants to reserve these habits for someone else he loves?
How far can a 'harmless' habit bend... before it breaks into a Yandere psychological horror? Is Gal-dom an evolutionary pathway to Yandere?