Conclusion after the end:
If you take out the whole, in my opinion, unnecessary vampire story, the series is a story about the love of your life and the luck of finding it. It's a story about soul mates who find each other again and again and finally grow old happily in one of their lives. Just as many of us humans wish we could have a marriage with someone we love with every fibre of our being until they both find their way back into the cycle of the earth.
The series should have either left the vampire theme alone or done it better (the vampires here are toothless, kind of like Toothless from How to Train Your Dragon, the Disney film). But the version here is really bad, unfortunately, and greatly reduces the rating of the series. I will therefore only give it one star more than my provisional rating. A wasted opportunity.

Review after 5ep:
The first two episodes were hard to take, my thoughts were "bad acting, weird main characters, a story that barely fits together". Even now after 5 episodes the story is still opaque but with the appearance of the "bad boy" it becomes more exciting, he brings in dynamism.
Overall, I'm only staying tuned because I want to know whether pun will bite yoh. Unfortunately, the vampire himself is also very badly staged, I've seen it done better in other East Asian productions like the Kdrama Blood for example.

Random thoughts on the series, may contain spoilers:
What the hell is going on with Somchai anyway? He may be a well-written character, but the actor is rubbish. He only has one laugh and the exact same sentence structure. There's no variance, you can't just hear if he's amused or pissed off about something or whatever. And his constant clapping...just super annoying.
It's a shame that Pun's story wasn't told more about how he became a vampire and why his father made a deal. This storyline would help a lot with understanding.