Senjutsu it’s a powerful technique that only be used by the best in ninja history. Minato, Hashirama, Naruto, Madara, Hagoromo, Mitsuki, Kabuto, and Jiraiya are the only ninjas, we ever saw use it. However, it now seems as if the Boruto Naruto Next Generations anime has shown us that Konohamaru may have learned it as well.
We all know that Konohamaru had been taught tons of techniques by his rival Naruto Uzimaki the seventh Hokage. These techniques are the Shadow Clone Jutsu, Toad Summoning, Rasengan, and the Sexy Jutsu. In addition, he’s also the grandson of the third Hokage. Konohamaru also mastered Hiruzen’s and his uncle Asuma’s secret technique. Which means he’s talented.
Now it seems that Konohamaru has taken another step towards becoming Hokage, as he is the leader of the new team seven. He’s showed us that he might have learned quite a bit in the time skip. When he defeated two ninja’s in team seven’s first mission. In the time between Naruto Shippuden and Boruto Naruto Next Generation. Konohamaru had learned the Rasenshuriken. Naruto invented this technique by fusing wind chakra into his Rasengan.
Konohamaru was seen infusing wind chakra into his Rasengan against the ninja’s that attacked his team. And if you remember, this technique has a huge flaw. It destroys the arm of it’s user, and it’s wielder’s enemy. Therefore, the technique was banned by Tsunade. This technique can only be used by someone using Senjutsu (Sage Mode). Yet, Konohamaru was seen using it, without using Sage Mode.
However, it’s possible that he used Sage Mode later to speed up the healing process. I mean just think about it. Why would Naruto teach Konohamaru all his techniques but Senjutsu? We already know that Konohamaru has the toad affiliation, and it proves that he’s at least learning how to use the technique that only a few have achieved. Konohamaru wouldn’t allow Naruto to skip out on a such an important lesson. That’s why Konohamaru has been entrusted with Team seven. And that’s why he can use the Rasenshuriken. As I believe he has already learned Sage Mode.