you need to pass 20 days without doing any lewd, the "blue bar" make it to 0 buy items in the park,
orange bar at 100%
red bar (lust) at 500%, dont go at 1000% this cause whore ending
blue bar make it to 0 it's make her less shy = more lewd scenes
last bar don't go at 100%, just leave it at 0, and dont talk with your boyfriend at night, avoid it with the second option, so this way cant level up the suspicius level
you can buy items to low and rise those stats,
for uncle you need 100% orange bar, 500 stat in lust (red bar) and 0% stat in blue bar
and after all scenes, i recommend you to cheat the days with cheat engine, after you got all scenes with uncle, you can skip the day with cheat engine to 60+ day, this will result in NTR ending with uncle, i love that scene
PD: uncle event triggers when you're taking an bath, he enter and saw you naked, after this, you can go to his room an start the events, first scenes use schoolgirl uniform, and later events use the uniform above bikini, that creamy color, sorry for my horrible english, hope it helps