I'm reading this again from the beginning, and now I'm 100% sure that Taesung's mom was in love with Haebom's mom, but because the last one loved Haebom's dad, she gave up and tried to live a "normal" life (get married with a man, have a kid...).
And that would finally explain why Taesung's mom abandoned him for seven years and why she loves Haebom so much... BECAUSE HE IS THE SON OF THE GIRL SHE LOVED.











So... Yanagi, who hurt you?