Sakura used to be quite a good unit but has lost some popularity due to new other releases.
She has quite a low ATK stat and an ok HP stat but does have a large attack range.
Her Ninjutsu costs 4 Chakra so is quite quick to use and has a large damage multiplier which helps to make up for the low ATK stat. The Ninjutsu can only hit a single unit and the overall damage is quite low so with the lack of any other effect is not the greatest.
One of her best features is that she has the Field skill to passively heal your other characters. This is what made her a good pick to start with but now each other character type (Body, Skill, Heart, Wisdom and Bravery) all have there own passive healers and most of them are better picks than her.
She will still find a use in certain raids/events that Body type will be good for.
Passive healing Field skill
Low ATK stat
Ninjutsu is a little unimpressive
Thanks to bfw182 for his awesome evaluation notes!
Here is an answer from a member of the team, bwf182:
Hello, you need two 1* body scrolls (blue) and you will also need two 2* body scrolls. You can get these from either the all scrolls events or the blue scroll day events which is on a Tuesday. Hope this helps
Answer to question.