Sorry for late reply
For about 4 hours i beleive. Though it used to be longer as i have had it for over a year and the battery not like it used to be.
Kde is the default desktop eviornment.
It helps that its a non systemd init system so it doesnt pull as much resources on the backend since systemwide is controlled via scripts.
If i were to run a lighter one such as xfce, qtile or dwm it would run longer(varies on configuration though)
I thought it was good, their dynamic was great, it was great seeing them slowly shatter the wall they started out with. Romance wise it was def above average.
As far as what i think can top it
kimi ni todoke (prob becsuse its various love stories that intertwine and you see the growth+ more innocense)
my teen romantic comedy snafu is another good one(love can become complicated quickly, really good)