To be honest, the beginning chapters were a great impression. Its a unique plot, and the whole topic was treated surprisingly maturely for a Japanese author. The protagonist seemed to actually care about the FMCs, and their interactions felt genuine.
However, it seems like the author has lost the plot, or they've begun to shift their topic. The story has sadly gone from something actually unique to just the typical fanservice borderline-porn. Instead of the protagonist teaching the girls, the ring was simply used to brute-force through everything and now the story is just about the protag getting it along with anyone, with simple plot-point discoveries that are introduced for single chapters to fuel a certain situation, and quickly thrown away when the chapter flips its page.
Its lost its charm. A bit disappointing.