Iruka is first introduced as Konoha’s  academy teacher. Iruka formed a special bond with Naruto, we find out that the kuubi inside him killed Iruka’s parents. So both of them suffered from a lonely childhood. But instead of hating him, Iruka took Naruto under his wing and protected him in his academy years. Later on Naruto [...]

Zabuza found Haku sitting on a bridge  under the frozen snow. He took him under the condition to serve only him. Zabuza has always treated Haku as a just a tool to accomplish his goals. But Naruto was able to let him look deep enough and make him realise that he loves Haku after all.
 

Jōnin (Literally meaning “High Ninja) are generally highly-experienced shinobi with great individual skill who serve as military captains. They are often sent on A-rank missions, and experienced jōnin may even be sent on S-rank missions (which are considered to be the greatest difficulty). It is not unusual for jōnin to go on missions alone. Jōnin [...]

Student of Orochimaru, Anko turned her back on him to stay faithful to Konoha.