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When li huan said "our parents", did he mean his dad and yu yang's parents? If yes, I thought yu yang was not in good terms with his parents but now their parents are like best friends..? Eeehhh? I just need some explanation.
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If you look at the date it says this extra happens in 2024 so a few years after the event from the main story, just like most of the extra.
And it's been showed many times that in the future things will get way better with Yuyang's parents, that Lihuan dad will sometimes be at their house and even that Yuyang's dad will kinda accept Lihuan as his son-in-law.
We just have to wait to see HOW it happened.
ε=ε=(ノ≧∇≦)ノ