A/N: I do not own VOCALOID or any of its characters mentioned below.
Rin brushed her teeth and stared in the mirror. She had placed her hairpins and ribbon on the bathroom shelf. She heard Len walking around in his room, probably searching for his pyjamas. Or his shirt. The shirt she was wearing. As soon as he took it off to change it for his nightwear, she took it out of his room, and renamed it as her nightgown. He probably wouldn't figure out where his shirt went, until she told him. He didn't pay much attention to what she was wearing.
She cleaned her toothbrush and yawned.
"I'm not a sleepyhead, I'm just tired," Rin said, turning around to face her brother. She rubbed in her eye with the back of her hand, trying to stay awake.
"It's funny how you are the older one, but I am the one who is able to stay awake way longer," an amused smile appeared on his face. He walked past Rin and grabbed his toothbrush.
"I'm not that much older. Like… 5 minutes?"
"There, you said it yourself. Now you can't go like: "'I know it better, because I'm older' anymore."
"Len! That was two years ago! We're older now." Rin said and punched her brother playful on his arm, almost making him choke on his toothbrush. "I'm going to bed. Goodnight." She kissed him on his cheek and ran to her room.
She switched off the lights and made her way to her bed, trying not to trip over her miniature road roller. She remembered leaving it somewhere around here on the ground. After hitting her foot at the controller of said road roller, she collapsed in her bed, gladly covering herself with the blankets.
The stairs cracked. Rin opened her eyes. "Oh, give me a break. I'm not even in bed for two minutes and I'm already hearing things…" she mumbled to herself. Something knocked on the window.
Scared she hid herself under the sheets again, leaving only a little room left for her to peek into her room.
She took a deep breath. It was nothing. She should try to get some sleep. "It's all in my head. It's all in my head. There are no monsters. It's all in my head." She kept telling herself, closing her eyes again.
A loud thud filled the silence and she swore she could hear the monsters move, trying to get closer to her bed, while breathing hard.
The light flicked on, and Len appeared in the doorway, worried look on his face. "What's wrong?"
Rin's eyes filled with tears, while running over to her brother. "I'm afraid of the monsters!" she sobbed in his chest, wrapping her arms around him.
"Aren't you a little old to be afraid of monsters?" Len chucked.
"It's not funny, Len!" she said, still hiding her face, making her voice sound muffled.
"Rin…" Len said. "Rin, look at me." Rin moved a little and stared into her brothers blue eyes. Len raised his hand and brushed away her tears. "It's okay now. The monsters are gone. And I'll make sure they won't come back, okay?"
She sniffled. "Will you stay with me? To keep the monsters away? Just like you used to?"
"Of course." Len pulled her close and kissed her on the top of her head. "After all, you are my princess and I'm your knight."