Review Detail of Yuri4Harem in The World seems Realistic but Why do I have a Leveling System?

it's only two chapter but i'm already liking it. i want more! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP! EXP!