User blog comment:TheShapeofThings/Collaboration- Konoha Genin Squad/@comment-25156300-20150102224728/@comment-25936981-20150103035131

Thank you for considering!

The time line between the First and Second Shinobi Wars is extremely vague. 20-odd years apparently passed between the two conflicts. What I've learned about the Second War is from reading the Naruto wiki and listening to Chiyo's dialogue during the Kazekage Retrieval Arc. Based on these, we know that the Second War was a four-way conflict between Konoha, Suna, Ame, and Iwa. It sounded like economy was the root of the problem, followed by countries expanding their territories. If there were any alliances, none of them included Konoha, as they faced enemies from Suna as well as Amegakure, where most of the fighting took place. I don't know what role Iwa played in the War.

It's possibly the war that Kakashi's dad participated in and killed Sasori's parents. Chiyo faced Tsunade and her medical prowess. The Sannin were given their legendary nickname during a battle with Amegakure's leader. Lots of the parents in the modern timeline were kids when this war took place, so your genin probably would've reacted with them. This was also the war that gave birth to the idea that every genin squad should have one med-nin, as suggested by Tsunade. She even personally trained future  med-nin during this time.

To be honest, I'm not all that far in Shippuden, so most of the things I know come from reading the wikia, but I think there's just so much that could be done with a character from this era.