It could be that 'nitro' here is just a name or a specific term, and 'the same old story' implies something that is a familiar or repetitive situation. Maybe it refers to a story related to nitro that is always the same in some way, like a recurring event or pattern.
Imagine nitro is a character in a series of novels. 'The same old story' would be that nitro always gets into the same type of trouble. He always has a conflict with the same group of people, and his way of getting out of the mess is always the same. For instance, he always relies on his charm to smooth things over with the local authorities, which has become a very familiar and repetitive pattern in the stories about him.
The 'nitro old friends new pain story' might be about a group of old friends who were involved with nitro in some way, like a nitro - based hobby or business. And now they are experiencing new difficulties or 'pain'. For example, if it was a nitro racing thing, new rules or competition could be the 'new pain' for these old friends who used to enjoy it more freely.
One possible theme could be change. Since it's about old friends and new pain, there has likely been a change in their situation related to nitro. Another theme might be loss, perhaps they've lost the simple joy they had with nitro before the new pain came along.
Nitro+ was a new online literature platform with many popular novels. Here are some reviews of Nitro+'s works:
1 Holy Ground: This novel is considered one of the representative works of Nitro+. It tells the story of a cosmic world full of imagination and sci-fi elements, which is deeply loved by readers.
2 " Battle Through the Heavens ": This is a very popular fantasy novel that tells the story of a teenager's growth. It is full of passion and battle scenes. It is very popular among young readers.
3 Ghost Blows Out the Light: This is a very popular tomb robbing novel full of thrills and suspense elements. The plot is compact and deeply loved by readers.
4 " The Peak of Martial Arts ": This is a fantasy novel with the theme of martial arts. It is full of actual combat and skill elements. The plot is full of drama and is deeply loved by readers.
5 << Full Time Expert >>: This is a novel with the theme of games. It tells the story of a gaming expert's growth. It is full of friendship and competitive elements. It is deeply loved by readers.
Nitro+'s works were highly rated and had many novels that were loved by readers.
This phrase implies monotony. Say there's a workplace where the boss always gives the same unachievable targets, and the employees always have the same struggle to meet them. It's a pattern that doesn't change, so we use'same old story' to describe this unchanging and often tiresome state of affairs.
One way is to step out of your comfort zone. If it's a personal 'same old story' like always choosing the wrong type of friends, be brave and make new connections in different social circles.