I been thinking, about Tsunade x Sakura. They don't seem to have a deep connection as Jirayia x Naruto and Shikimaru x Asuma. Tsunade always have been like a mother or grandmother to Naruto, just like Jirayia always been a grandfather to him. I mean Chiyo and Sakura had a deep connection even though for only a short period of time. Chiyo acted like a grandmother to Sakura ever since they first met and fought Sasori.