Ah, what a great game. I never forgot the surprise this thing give me when i trying to harem all the girls on same run and the childhood friend waifu blocked me for already banging her friend.
oh I loved that game so much in the 90s! I am always looking for games similar to this one for the training elements. Workouts to appeal to the sport chick, work on your style to raise your good looks, study to appeal to the elitist smart girl, work to earn money ect. Does anyone know of other games with a similar system?
Hard to say since True love is one of a kind. You still can grab some of the feeling on others games.
From the top of my head, i should say your best choice should be Tokimeki memorial. Same year, not hentai, and its the game True Love got based on. There is a port to PSP patched to english. This genre got a lot of games in japan, but since its got so much text, its really hard to find a translation.
Someone told me about Tokimeki Check in! as a hentai version of those, but i never played it.
On the visual novel side, three sister´s story, seasons of sakura, Runaway city, nocturnal illusion and divi-dead are also from 90´s and always spots on the same lists as True Love, mostly about the same art style and the nostalgia feeling (tough the last two got a more dark aproach and dont have the high school vibe).
If you go for RPG, Knights of Xentar and Cobra Mission also got it (Cobra mission have his own value also for being a JRPG in future setting without turn combat system).
I also remember of Maid´s Story. A totaly different setting, but have some time management and hentai.
Princess maker is another nice non hentai management game from the same decade. On his hentai counterpart, the closest thing i can think on a gameplay like is SimplyMind (pixart hentai), but with a totaly different feeling on the story (since game plays in hell).
Stretching a little to much, you can go for brothel games since they usualy have time management (Strive for power, Slave Maker, Wicked Rouge)
Also i usualy see katawa shoujo popping up everytime i search for true love. Its a very specific VN, but people say its realy tender on the history side.
Hope that helps. Still searching a spiritual sucessor to True Love. I give you the tip if i ever found something.