The eight chapter, the one about Otenba's mom.

Yamazakura looked at Otenba, reached into a silk purse, and held a necklace that had a wolf's tooth with a star sapphire in it.
"This was your mother's necklace, she called it her 'sky-gem', when the accident happened, her dying words were that you should have it. It might have lost the magical powers that it was supposed to have, but it's got your mother's love."
Otenba put on the necklace, it seemed to cast an pale yellow glow, but Otenba thought it was just the way the light hit it. Mac looked curiously at the jewel, with his head cocked to one side and filled with questions; What were the sky-gem's magic powers? How did Otenba's mom die? Why did Otenba and her family leave Japan? Why did Otenba go out by herself to find Foster's? Why didn't she tell him all this? And why was Duchess spying on Otenba with hate in her eyes? When he and Tenkyuu were helping Otenba and the rest of her thier family unpack, he dropped a tape. Mac noticed the tape, the label said somthing in Japanese. Mac picked up the tape and carefully waited until all the things were unpacked. "Say, Tenkyuu, what does this say?" Mac casully asked, showing Tenkyuu the tape.
"Oh, it says 'Hikarimono's last days'." Tenkyuu answered without thinking.
Mac then ran off to look for Bloo, This might answer a few questions, he thought.
"Bloo! I think I might know what happened to Otenba's mom!" Mac shouted in excitement.
"Who cares about Otenba's mom? She's dead, and we can't do anything about it." Bloo dully replied.
"BLOO!!!!!!! HOW COULD YOU SAY SOMTHING LIKE THAT?" Mac yelled, and then he got a pretty sly idea. "Oh well, guess the death of Otenba's mom is a secret door is somthing I alone have to open."
"SECRET DOOR?!?!?!?!" Bloo said as he dragged Mac to the very TV that Eduardo, Frankie, Wilt and Coco were watching "The Loved and the Loveless" on.
"PLAY THE TAPE! PLAY THE TAPE!! PLAY THE TAPE!!!!" Bloo excitedly chanted as the hero and heroine of the TV show were about to kiss.
The screen went blank, and then there was a young woman in front of a big house on the screen. She had wolf like ears, a tail, her long, grey hair was in a loose braid, and she was holding a familar-looking five-year-old in her arms.
"Pause! Doesn't that girl look familar?" Mac said as he pointed at the child in the woman's arms.
"Yea, she looks like Otenba," Bloo said, squinting and cocking his head.
By this time Frankie was furious, that was two time Bloo had somthing to do with her missing kissing on 'The Loved and the Loveless.
"What's going on Bloo?!" She demanded.
"Detective work, Frankie." Bloo replied.
Mac watched the tape and took notes. One scene was sad, the woman and 'Young Otenba' (as Mac and Bloo dubbed her) were walking down some steps, and the woman tripped and fell down the steps, and then a heavy-looking bookshelf fell on her, and she started to bleed, and soon, the woman was a mess of blood. Young Otenba was at her side crying "Mama! Mama!" as tears streamed down her face. The woman was crying too, and said very weakly, "Otenba mai koishii....." After the bookshelf scene, the woman was in a hospital bed, holding a younger-looking Yamazakura's hand, giving her the sky-gem, and saying a long string of Japanese words. The woman and Yamazakura looked incredibly sad, and then, the woman's hand fell, and she stopped breathing. The screen went blank, and Mac turned around to see Wilt, Frankie, Eduardo, Coco, and even Bloo crying thier eyes out. He looked at the notes he had taken, and noticed that they were tear-stained, and relized he was crying, too.

It think that was sad, I mean, someone died.