Overall I somewhat enjoyed this series, but...
This is a 16 episode comedy/drama done in 40 episodes. I've seldom seen such a long, drawn-out, repetitive show.
Some of the characters are semi-engaging, but remain 2-D throughout. This isn't exactly a one-joke show, but it's a dozen sub-themes repeated every episode. The story theme was so extremely repetitive that by the 20th episode I wasn't sure if I wanted to continue watching this. By the 30th I was absolutely sure of it, but by then I had vested so much time in it I had to see how it ended.
The humor is droll. In the entire 40 episodes I think they got 3 laughs out of me (and I enjoy comedy). Even tennis fans will likely be put off by this highly-fictionalized representation of tennis . By the end, some viewers will probably not care whether the team wins the Nationals or not. Just get it over with! (I got sooooo tired of "boomerang snake" moves.)
Had this been 12 to 16 episodes long with the story properly compacted to keep the viewer engaged, this might have been tolerable. But at 40 episodes it just drags on. Okay we get it: personal relationships and one's viewpoint of life is important. Never quitting is important. We know, we know... especially by the 40th episode... we get the point.
Decidedly NOT "binge-worthy"; about halfway through many will wish they'd never started watching. The series overall doesn't disappoint as far as overall story line goes... it just takes a very long time to get there. Can't put this is on my top-ten list of Asian series. There's just too much plot repetition to make it a truly enjoyable watch.