Heya! My hints are:
Pic 14 - Achieve between 5-7 affection across the whole date, but for the key choices after lunch (i.e. hold his hand, to keep or reject the plushie, to intervene or not do anything), don't pick options that gain affection. The game allows you to pick up to TWO "adds affection" responses for post-lunch choices without triggering the true ending.
Pic 15 - Achieve between 5-7 affection across the whole date, and ensure that for all key post-lunch choices, you pick the responses that GAIN affection. Look out for times when Liev opens up about himself, that's a way to check that you're on the right track.
Thank you so much for playing! I'm really glad you're enjoying it ^^