he did more than that!
If you don't want spoilers stop reading now: he built a company to sejin (and make he get his degree in perfume making), so he can be financially independent from his father and even Ido himself. he stop sejin's father when he would set up sejin to go to jail. And he didn't expect to sejin to stay with him, so after everything was work out for sejin he was planning to kill himself.
I don't remember exactly bc I read on mtl but basically was: When sejin is independent and financially stable Ido breaks up with him, Sejin doesn't accept it, they fight and Ido end up making Sejin (its when he remember their past life). He get EXTREMELY angry with Ido, they talk about it and Ido beg forgiveness but doesn't expect they to be together.
They break up and Sejin stars therapy to threat his trauma of being raised by that awful family, the rape and he killing himself pregnant. After three months they meet again and have a conversation about everything that happened in the past life and on their current timeline (sejin is able to feel ido's feelings and he know that Ido is basically suffering 24/7 since the break up , it makes him happy for some time but it starts to make him sad as well)they start to work together of a few weeks, and the end of this jobs Ido says goodbye to Sejin, its when sejin found out that Ido is gonna kill himself so the bond between they break and he would be able to have a new partner. Sejin realize that after everything he still loves Ido and ask him if they can start everything again, really slowly this time.
will sejin recall his past life? i sure hope not