One of my biggest surprises while reading Naruto Retsuden was that the author took the time to describe Iruka's relationship with not just Naruto, but also added brief descriptions involving most of the Rookie Nine.
Sakura and Sasuke are both explicitly stated to trust Iruka, with Sarada staying with Iruka for a month long homestay while Sakura and Sasuke are both away on mission.
Ino, Shikamaru, and Chouji turn to Iruka to look after their children when they themselves cannot be there to protect them while village is in danger, with Inojin, Shikadai, and Cho Cho all staying with Iruka and Sarada when all their parents are called to duty.
The fact that most of the Rookie Nine would entrust their Iruka Sensei with their most precious people implies not only a high level of respect but a close personal relationship as well. And it really warms my heart to see that Iruka is depicted as not only important to Naruto, but remains as part of his other students' lives as well.
Tidbits like these alone make Naruto Retsuden worth my while.
Also, Iruka watching over all the Boruto generation kids since they were ankle biters is now firmly part of my headcanon.
