Managed to get the [Love] token. First you need to have [Trust], then you can use the flirt talk command when you have maxed Charm stat (the bottom tentacle in the upgrade menu). After you do that the trust token changes to [???] and the next time you enter there will be a short dialogue after which you can choose to become lovers.
... that said, maxing up Charm takes fucking 3850 skill points, I don't see a way to get it legitimately given how little points you gain, even if you were buying the +100 skill points drink every day.
Cheat Engine works for this, you can edit both SP and cash. For SP scan for Float values, for money 4 Byte values.
Another tip, patch up your game with unity autotranslator, it works alright and -usually- has enough time to translate the girls' lines as they say them, that way you can play on Jap setting and see the REAL skill descriptions, since on Eng some of them are missing and some are straight out wrong.