The ending was great, story was fine. But author somehow let us in the mist what of the brother's childhood friend. Was she into our MC too? Any way the read and art wasn't bad at all. Thanks for the translation!
It seems that the missing chapters of vol.4 were never published. That's why they're nowhere to found. It's really unsettling, but the story was ok. At least the ending was satisfying. Cheers!