Across the Long River of Time, It Is Difficult to Reconcile People's Hearts

It's the story of the twins Deha and Ha who fight the boss and change the past. Twin Snake Yard setting! Don't like to enter by mistake! The ending must be he! Happy ending! Don't criticize anyone (except the villain) and try to describe it objectively I am a sophomore in high school who specializes in piano. I am busy with my studies and the update time is uncertain, but it will definitely not be a scam! I am a new writer, new to Deha, please give me some advice?? If you think the plot is unreasonable or the characters are OOC, you can mention it. If the suggestion is good, it will be modified. Okay, that's it, let's read the article. Intention: Invincible love