WARNING: The following contains spoilers for Episode 6 of The Slime Diaries, "Changes," now streaming on Crunchyroll.
Episode 6 of The Slime Diaries celebrates yet another gathering, fresh off the high of the festival in Episode 5. This time, Rimuru suggests a Bon Festival, which is readily accepted after his brief explanation of what it entails. In Japan, the Bon Festival has been going on for over 500 years. It's a time when families come together at their ancestral living place to take care of the graves and pay respect. Over the years it has evolved into a family reunion-style holiday and is celebrated every summer.
Rimuru, having come from our version of Japan, knows about the Bon Festival and decides to introduce it to the citizens of Tempest. He tells them to gather with their respective clans to share stories, reflect on their ancestry, and deepen their bonds. Then, the clans can come together as citizens of Tempest to grow their community bonds as well.
The Slime Diaries highlights almost every clan as they take the time to reflect and notice changes. The Ogres visit a grave and set up a little shrine in dedication, featuring multiple blades and a pinwheel. The Lizardmen chieftain receives a visit from his daughter, Souka, who comes bearing a gift and updates about Tempest. While she's there, the chieftain offers her multiple marriage proposals from different suitors.
While Souka's visit isn't exactly a clan gathering, she pays homage to her father and spends time with her ancestral roots, even if it's only brief. Episode 6 does that really well, showing how spending time reconnecting with family can be a simple thing, like a short visit. Even Clayman, who That Time I Got Reincarnated As A Slime sets up as a villain, has his own moment with his family of Demon Lords as he bakes them his famous scones.
Even Rimuru, who is alone in this world without any blood family, gets a moment to reflect on his roots. He takes stock in the fact that he is a slime with the appearance of Shizue, another Otherworlder from Japan. Upon her death, Rimuru eats her body and thus transforms into a version of her. But her spirit is kept alive in this way, as seen throughout Episode 6 as the ghost of Shizue watches the Bon Festival.
In the last scene, Rimuru sits in front of a makeshift shrine for Shizue and talks aloud for her spirit to hear. While he prays, the ghost of Shizue speaks back to him. Rimuru catches some of it and instinctively responds, but at that moment the incense mysteriously goes out and he's left alone to realize he was speaking to someone. Even Rimuru gets a moment to connect with his ancestor of sorts.
The Slime Diaries Episode 6 shows the importance of strengthening the bonds within one's family and community, especially when people of different clans all live together. Rimuru brought a real-world holiday into the isekai world of Tempest and it helped reconnect everyone, including himself.