Couple of things i have found... 150 trust is needed to bathe together, 200 is needed for you to talk with each other. getting to 20 sexual interest will allow her to let you touch outside the crotch without the bad meter going up super duper fast, 100 lets you insert and she likes it, 150 allows you to turn her around, which allows you to start anal training. you must anal train with fingers for a few days, then toy, then you can go to dick. the bad meter goes up pretty fast for anal training.
for the beginning of the game, just rush trust to 150, start bathing together (requires good mood or better), then you gain 2 sexual interest automatically, lewd talks give 1 or 2, and some romcom shows give 2. getting to 20 is the start. every time you make her cum you get 15-20 sexual interest, to the point where if you get to 100 so you can insert, and make her cum multiple times, and you cum a few times, then you can turn her around and start anal training in the same night if you have time. currently i am on day 30, i have the massager, anal vibrator, 30k yen(need 50k min for good ending) and she is perpetually in a good mood.
some notes: if you are a part timer or bum, walking the neighborhood 3 times gives 1 energy.
workout gives 1 energy, 5k yen for pool gives 2 energy (to max), I find that 60 energy is the sweet spot for me, i can balance everything.
Sleeping at different times yields different energy restores. 30 seems to be the minimum, 55-60 the maximum. so if you sex on friday night (turning to saturday) and go to 6am, you will get very little energy.
Friday night and saturday night are the best times to have sex, they can last until 6am, while weekdays (sunday night leading to monday, through thursday night leading to friday) you can only have sex until 2am, though there are times it will go to 2:30am.
the anal vibrator is a necessary purchase, you must have this to get all scenes unlocked. the electric massager unlocks squirting. everything else really isnt necessary in my opinon.
the training machine and dumbbells are a waste of money unless you start with less than 35 energy and you dont want to grind.
save before every sex. sometimes she just gets mad. also dont do sex every day, it affects her mood when she doesnt sleep... like a normal person.
if you want to have sex, you must look at her vagina before touching, you also must look at her panties before you can open her legs, and opening legs means panties come off with 1 try, not 3.
if you want to pull her pants down to "molest" pull down, look at face, pull down, look at face, pull down, look at panties, open legs, take panties off, look at vagina, then go.