Why do people think you can send roses only for that mission? You can send 30 shurikens (one per day ) and 15 roses (*s if you are f2p like me ).

And getting 15 friends to lvl 6 is just a huge pain... Its possible but it takes 2 much effort. Most of the friends are already 10+ lvl. And people who are under lvl 6 are not active for a year or two now. Im sure its same for most of the people.

Yes you can send one shuriken and 3 ninja task missions per day but unless you make few alt accounts and get them to friend lvl 6 it will be almost impossible to fini*. I