At your own risk!
You sure want to spoil the ending thing?
Fine! HERE IT IS!!!
From my understanding of the ending... MC and ML are from the distant future. Very distant future. Do you want more?
This is what from my understanding:
In their current era; after thousands of years of human genes kept evolving becoming more and more powerful and perfect genes. The former inferior genes has long been extinct. Apparently there was a long-lost ancient gene called 'White Lotus' gene on their parent Blue Star (Earth highly chance they meant) in the novel's lore.
There was even a legend: Whoever has or uses the White Lotus gene can bring endless disaster to the people around that person. If this disaster kept on expanding, even the whole world is destroyed. So the descendants of humanity who survived the catastrophe in all those years ago, didn't want it to happened again.
So the Empire (where MC and ML are from) made a new game called: White Lotus. This game was made to make everyone be aware of the of how deadly the White Lotus gene is. This made people go to the hospitals to check their genes for fragments of the White Lotus gene to have it removed from their body. There is a reason for me to put this explanation.
As for MC's and ML's position in their world? From my understanding is the MC and ML knows each other quite well. They were already lovers in their real world.
MC is the programmer of the "game".
MC paid countless hours to create the game. As he about to complete the game, he didn't know how or why did a loophole pop up in the game system. In addition this loophole in the system cannot be fixed (you'll know why). Thanks to the loophole the former tester was actually locked in the game and couldn't come out. In order to figure out what happened, MC decides to also enter the game. But what he didn't know is the ML actually followed him.
Thus the main reason why MC was inside the game.
ML is the provider of core technology of the "game" so he has higher authority than MC.
When MC entered the game ML followed him. During that time, ML sealed (abuse of power!) all of MC's memories to make him fall in love at him again.
Main reason for ML to entered the game was to get along with his wifey and another reason was because the "game" has the courage to marry his wifey (I think it meant the actual game like making MC marries an NPC because that how you need to play and finish the game) !
But once he entered the "game" he found the so-called loophole in system was.
Truth about the whole thing!
Anyways MC put too much attention and feelings on the process of writing for the game. To make a more realistic portrayal of White Lotus, MC searched for countless materials about White Lotus for the game. To the point the he kept on updating again and again until it was a perfect White Lotus. As a result of MC's seriousness and dedication, the White Lotus in the "game" gained actual consciousness and feelings. And those feelings were towards MC and wanted to marry him...
So the "game" made a loophole in the system causing people (or tester) to investigating the problem. In the end the problem was not being resolve but also added a problem on detaining the people inside game. The system was trying to get MC's attention by causing more problems for him to look into it and trap him.
Of course it worked and MC went inside the game to look for this problem.
As possessive ML is, he followed wifey to the game and found out the whole charade...
After all he whoever tries to take his wifey away... Say bye-bye to life.
Are you really sure????
Fine! Here it is!
** Spoilers **
ML is real name is [Adam] (Probably different if its translate but that was MTL gave me). ML is also the system that give MC the task before it 'malfunction' to manual mode. But his actually origin that he is a TREE. That's right a TREE. Want more spoilers??? On your own risk!
ML is been alive for years as for how long, it didn't really specify. But probably thousands of years after all he is a tree. He himself doesn't remember when he start to have consciousness. It did say that ML see the changes to where he was planted. He was planted or moved (I don't know which is it) in some small town in the country side. As for MC he was living as a child there because he was sick and his parents were busy from work. His grandfather was the one taking care of him. That's where they first meet.
I'm not going thought the details but it is quite sad and yet heart warming, So looked at it your own risk from the raws.
Ending Story 1 (Future Interstellar) and Ending Story 3 (Virtual World Game)