Arbiter with human emotions, that Nona mentioned, is not Decim but Chiyuki.
All arbiters show emotions of some sort so the one Nona mentioned should have more of that. But as far as all the hints go to Quindecim Onna is the main suspect.- Also the Chavott book and Nona's interest in her.
- And it will be easier to mask the subject as temporary helper not the actual Arbiter.
- there's also Nona's last words to Onna in episode 2, and the bit in the elevator with where Nona tells Clavis that she's got ways to go
- Jossed. As it turns out, Decim is an arbiter with human emotions because Nona implanted them in him. While Chiyuki is an actual human who somehow was aware that she was dead when she first entered Quindecim.
Yagami Light somehow talked Ginti into sending both Harada and Mayu to the void in order to secure his reincarnation.
There's no question Light can think on his feet, and may have played on Ginti's disdain for humans and his sick amusement. The two humans who were judged incorrectly in the 1st episode are recovered in the 2nd.
I think it's pretty heavily implied that Nona's job is cleaning up every other Arbiter's "occasional mistakes". Since these two humans in particular are referred to quite often in later episodes without the slightest shame or regret involved (even from characters with real human emotions), it seems like it wasn't too much trouble to recover their souls and have them sent to their proper place, or having them re-evaluated by a different Arbiter. Death Notes exist in this universe and that's why humans are dying so fast.
That's also why Light himself made a cameo appearance. The Arbiters know who is responsible.- Makes sense, with even a bit of Fridge Brilliance. "The human who uses the notebook can neither go to Heaven nor Hell." That's because he's sent to the Void.
Ginti was another attempt at giving Arbiters human emotions.
For a being who is meant to have no emotions he sure acts emotional, more so than Decim in fact. What if there was another attempt at creating an Arbiter who could feel only it didn't work right or did not produce the desired results. As it would have been either two difficult or to noticeable to have him completely reset and since he was doing decent work Nona decided to leave him at it.- Alternatively Ginti and Decim are two sides of a still ongoing experiment by Nona watching how emotions effect an Arbiter's judgment over time and with different experiences.
- Alternately, Ginti was given human emotions, but they were negative ones as opposed to Decim's positive ones. While Decim shows signs of being compassionate and having self-reflection, Ginti is shown to be petty, rude and spiteful. The only other Arbiter we see "at work" is Quin in a flashback but she at least appears to be civil to her guests, which suggests Ginti's an outlier.
Ginti kept Mayu around so he could find a reason to send her to the Void.
Ginti's often shown to be disdainful of humans and even looks down on them. It wouldn't be a surprise if he looked for whatever excuse he could to justify sending someone to the Void. But then Mayu sacrifices herself for Harada (or at least seems to), which shocks Ginti. He can't comprehend someone being that selfless, so he keeps her around to find something that will prove to him that she wasn't. When Mayu agrees to send someone to the Void in exchange for Harada's soul, that's enough proof for him that she was only acting out of self-interest, thus she deserves to be sent to the Void. Ginti was unable to accept Mayu’s selflessness because he was vexed by her obsession with Harada.
In a moment of petty self-pity, Harada picks up one of the wooden dolls Ginti keeps on the counter only to then drop it on the floor just to gawk at how Mayu looks in a kimono. This was apparently enough for Ginti to ignore the good in Harada and send him off to the Void despite him showing a trait that would normally justify reincarnation (risking his life to save Mayu). Perhaps Mayu’s obsession with Harada is the reason he ignored her self-sacrifice and contrived a reason to send her off to the Void along with the fumbling idiot who disrespected his memento. Nona arranged the Mayu-Harada gig for Ginti as karma for starting a fight in Quindecim.
It's already an unbelievable coincidence that Mayu should slip on soap and die right at the same time that her favorite pop idol gets blown up by a time-bomb. It's suggested that Mayu actually died well after Harada by the fact that, despite every other guest pair arriving at the same time, Mayu arrived late enough that Harada was already sitting in the bar waiting by the time she left the elevator. It's shown in later episodes that Nona has enough pull over Castra to be able to manipulate which humans get sent to which arbiters, so it's quite possible that she had Mayu paired with Harada and had them sent to Ginti despite them not dying at the same time. Tatsumi is inspired by Kira to become a vigilante
Since Light appears two episodes after Tatsumi's death, it can be assumed that Tatsumi dies around the end of Death Note. He has certainly witnessed Kira's killing spree in life, so it's reasonable to assume that his vigilantism is in part inspired by Kira. Time goes much slower in the after life
Nona noted that Decim has only been doing the job for 5 years, but in his bar, we can see mannequins with clothing from at least a century or two back.It also explains with the sheer number of ppl dying every day, whether there is an enormous amount of arbiters working to make sure the whole system runs smoothly, or the limited amount of arbiters are given much more time to work. The second seems to be a more probable explanation