What does Minato's teleportation kunai say? So I've been wondering what Minato's teleportation kunai said, but I have found nothing. I can only recognize the first and second characters. The first one means Shinobi, and the second one means love. I can't understand the last two.

So my question is if anyone knows what Minato's kunai say.
忍愛之剣 (にんあいのけん 又は しのびあいのけん)

Sword of Shinobi's Love

That image is not accurate. The person who drew the picture clearly didn't pay much attention to the characters. 

There is a YouTube video called "Did Naruto lose his six path sage mode" The cover photo has these four characters

Also, if you google these 4 characters, you will see there were a lot of people that have asked this question before