Aoi x Naoto... Awww... they were really meant to be together, weren't they?
In episode 40, the little boy whose favorite Jewelpet is King, the most unpopular Jewelpet. He played the crane game a whole bunch of times to get a plushie of him.
The First Kiss between Rinko and Akira in episode 48. And later in episode 52, they were about to kiss to in the end until Ruby barged in.
Diana and Dian now being happy with their new human partner while they babysit a baby.
Episode 30, which is about Akari's mother's birthday. Akari's mother realizes how much Akari's been suffering because of her giving more attention to Monika, and tells her she loves her just as much. Earlier, she had told Ruby that when she's tired, she looks at pictures of baby Akari to cheer herself up. Akari flashed back to the events of those pictures and realizes that her mother really does love her. The emotion of these scenes also makes them big contenders for Tear Jerkers.
Episode 39 is chock full of it, from Akari and Yuuma having fun together on his birthday to Yuuma meeting Opal and seeing memories of Alma and Fealina.
The ending: Akari is the new holder of the Jewel Star title and managed to turn Alma good again and reunite her with her family after many tribulations.
Mikage and Kanon reuniting as siblings once again in episode 46. To summarize this: In episode 41, Kanon found a photo of her and Mikage as kids, and she was shocked by it. It was in episode 45 when she and Mikage found out they were twin siblings all along. Episode 46 shed more light on the subject: both of them were separated during birth because Kanon has a spiral birthmark that could link to a future disaster and was forced to live with the Mizushirou family. After a few dramatic scenes, she breaks off her relationship with Mikage and accepts him again as her older twin sibling, to which both families agree.
In episode 51, after the rest of the Wise Ones get knocked out, Kanon and Ruby run to the school's rooftop and share an unexpected Friendship Moment, where Kanon confesses to Ruby that she really values their friendship and that she had always wanted a friend with whom she could argue without much consequence. Ruby reciprocates the feeling.
The ending of the final episode is a romantic Tear Jerker between a certain Jewelpet and Ruby. Ruby met a Jewelpet named Granite, who had the same voice as Mikage until she found out it was him all along. She broke down and ran to him in tears, calling him a jerk for not appearing in the last 5 years until she forgives him. They're happy to be reunited after all these years.
Ruby forgiving Pink at the end of episode 22 after all of the trouble she caused, all thanks to King. All she has to do is say sorry.
Midori obtaining the Deco Stone with his bare hands in the Legendary Obstacle Course in episode 36. It's also a heartwarming victory for him against his older overprotective brother.
The entire 50th episode. Everything in the episode focuses on Ruby trying to maker Pink remember who she is.
The scenes between Chiari and Kosuke in each episodes. At this time she is needing some motivation to confess.
Rossa and Labra's alone time scene in Episode 2 regarding the missing Magic Gem. May count as a big Ho Yay moment.