Kasumi Nakasu

"'The Stormy Thunders, Yellow Witch!'""-roll call""'Wielding The Powers Of The Ancient Lightning, Ancient Yellow Witch!'""-second roll call"Kasumi Nakasu (中須かすみ) is Yellow Witch of the Nijimen. She wields the lightning element.

Personality
While acting all sweet and innocent, Kasumi is actually bratty and gets jealous very easily. Despite her flaws, she is very caring. She can be very demanding at times, much to the annoyance of her teammates. She has a crush on her childhood friend Setsuna but gets annoyed because of the latter's obliviousness and also feels guilty, blaming herself for Setsuna's sudden over-heating of her fire powers.

Background
Kasumi's father was the leader of Nijitopia's Lightning Nijis. When the Darktopian Buccaneers invaded the magical kingdom, her father was killed, forcing her mother to flee into the human world, where Kasumi grew up, not knowing her Nijitopian heritage.

She and Setsuna are childhood friends. Kasumi gets annoyed with the latter spending most of her time studying on their school breaks but gets concerned with her well-being. Unknown to Setsuna, Kasumi is only angry at her because she has a crush on her.

At the end of Chapter 1, Kasumi witnessed the Niji King defeat Pirate Swashbuckler and also witness the Mahou Gattai Niji King: Ice-Wind defeat Pirate Facemaker. In Chapter 3, Kasumi steals Ayumu's lunch and innocently lies to the latter that it wasn't her. Setsuna asks her why would she steal Ayumu's lunch but Kasumi doesn't tell her why. Later, she finds the Thunder Niji Diamond and bonds with it after saving Cyan Witch and White Witch and realizing that she shouldn't act innocent just because she's cute. With that, Kasumi becomes Yellow Witch, wielding the lightning element. She then summons Niji Thunder Garuda to form the Mahou Gattai Niji Knight.

In Chapter 26, Yellow Witch becomes Ancient Yellow Witch after getting the Ancient Thunder Niji Diamond.

In Chapter 28, Kasumi ends up telling a lot a lies about herself, claiming she's the leader of the team, causing her teammates to no longer trust her. She quickly learns her mistakes, realizing that she shouldn't be lying about herself because she is still her no matter what.

In Chapter 36, she gets angry at Setsuna for spending too much time on study, causing the latter to get angry at her as well, saying she is too naive to understand. After Pirate Anger causes Red Witch to get even more angry and start to dangerously overheat, a guilty-hearted Kasumi decides to save her on her own. Though almost got killed, Yellow Witch pushes herself and Red Witch towards the sea. As they are stranded on the beach, Kasumi apologizes to Setsuna about earlier, which the latter apologizes as well.

In the final battle, Kasumi is the first to get killed by Space Captain Erebus and dies on Setsuna's arms with a dying "I love you". After joined by the rest girls apart from Ayumu, Kasumi and her team face against their revived enemies. After defeating them, they were resurrected back to life to aid Ayumu to defeat Dark Warlock Captain Erebus. After the final battle, she and Setsuna start dating.