Haru - The Ace

Haru - The Ace is available as a Trial Operative in Story Missions 7-10.

Haru's standard skill allows her to deal accurate damage at extreme range, affording her good survivability, and as a support her support skills short cooldown makes it highly spammable, and her ult can add a lot of damage to operatives with high-RoF weapons.
Haru's ult has a high U-Energy cost that means its dps isn't great, her standard skill doesn't really deal more damage than just shooting, and she doesn't really do anything special, which also means she really doesn't have much synergy with the common support operatives.
Overall, Haru is fine to play if you like her, but even among the 4* operatives there are better operatives you can use both as your main dps and also as a support.