HuniePop 2 is a serious step up in difficult over the first game. The new puzzle mechanics are causing some wannabe Letharios to run into brick walls when trying to get through the game.
Part of this is a double stamina system. One system is active during dates, and you need to match the correct white tokens to give the girls more stamina. The second one is active outside of dates, and restricts your interactions with the girls. Any time you ask them a question, give them a gift, or take any other action with a girl outside of a date, her stamina will go down.
This forces you into choosing when you want to talk and give gifts, and when you want to try and go on a date. It is a good strategy to focus on one girl before a date, so the other girl will start will full stamina, allowing you to focus on connecting Tokens for her, then switch to the other girl.
A big problem people are running into is that they hit a point where none of the girls have any stamina left, making it impossible to give them gifts or speak with them. The solution to this is simple, just go and take a nap in the hotel room.
Open the HunieBee by pressing spacebar, then click on Finder, and Hotel. Select the nap option and set the time you wish to wake up and the girls will have more stamina, allowing you to once again speak with them and offer gifts.