I hope that works out for you!
And here's the specifics, instead of just some hints;
-Lu needs to have three affection points by the start of Night 2. That means saying he has worth after sticking with him during Night 1 then spending time with just him during Day and choosing both options that show concern/kindness towards Lu
-Margret needs to be alive on Night 2
-When deciding to throw the lantern or just watch, you have to remain undecided until the time runs out
-Finally, when the guide has left Margret and Kikka to wait, you have to go check on him