Over the course of the series, Haru has worn many different outfits varying in design and culture. The ones known are listed below.
Namahage
Haru's namahage costume. It was first seen during the Daily Life Arc. Haru likes the costume Namahage and is seen wearing it most of the time.
Knight
Haru's knight costume. It was first seen during the Daily Life Arc when she was chasing Tsuna.
Kimono
Haru's kimono costume. It was first seen during the Daily Life Arc when it was New Year's Day and Reborn gathered Tsuna's Guardians at the time (Gokudera, Yamamoto, Ryohei) to compete against Dino's Chiavarone Famiglia.
Disguise
Haru's disguise costume. It was first seen during the Future Arc when she was helping I-Pin escape the Vongola HQ to go to a hospital.
Haru Haru's Interview: Dangerous
Haru's Dangerous Interview costume. It was first seen during the debut of Haru Haru's Interview: Dangerous. She is seen as a chibi.
Regent
Haru's Namimori Middle Disciplinary Committee costume. She has a regent hairstyle, as well as the uniform.
Choice Arc
Haru's choice arc suit; worn when the spectors were watching the fight between the Vongola and Millefiore.
Bikini
Haru's bikini outfit.
Mole
Haru's mole costume. It was first seen when Haru, plus Lambo and I-Pin were in mole costumes to help Tsuna and the gang look for the school time capsule.