If you are confused with the timelines, it basically boils down to:

1. Present time. In E01, this was 6 months after the diving accident of Momo. Of course the present time is moving forward.
2. Past 1.0 is 6 months before Momo's accident.
3. Past 2.0 is 9 years (I can't remember exactly) ago.

• As of E02, Momo hasn't appeared in Past 2.0.
• Past 2.0 is primarily about BaRa and her crush.
• Part 1.0 is also primarily about BaRa and her crush, with Momo and Dr. Shin's budding love as close secondary.
• Present is where Momo, her mother, and Dr. Shin comes to the front, while BaRa and her crush becomes secondary.

I suspect that they will all converge and some weird connections will surface or unexpected relationships created.