The morning light spilled through the curtains, warming the small bedroom Kei shared with his younger sister, Hina. At sixteen, Kei had learned to wake early, slipping out of bed to prepare breakfast before anyone else stirred. It wasn't a chore he resented; it was his way of making sure Hina started her day with a smile.

"Morning, Kei!" Hina's cheerful voice rang out as she entered the kitchen. Her dark hair was still messy from sleep, and her school uniform hung slightly askew. Kei turned from the stove, flipping a pancake onto her plate.

"Morning, sleepyhead. Fix your uniform before Auntie sees you," he teased, ruffling her hair.

Their aunt walked in moments later, followed by their uncle. The couple exchanged a few words about the news playing faintly in the background—a report about sudden temperature drops in a nearby city. Kei barely listened, too focused on getting Hina out the door in time.

The walk to school was calm. Yui met them at the corner, waving enthusiastically. Her energy was infectious, pulling Kei out of his usual thoughtful silence.

"You're late!" Yui teased, skipping to match their pace.

"Not my fault," Kei replied, smirking. "Hina couldn't decide which socks to wear."

Hina pouted, but Yui laughed. The three continued down the quiet streets, talking about school, upcoming tests, and Yui's latest ridiculous idea to start a "secret detective club." Kei only half-listened. Something felt... off. The air was unusually still, the usual hum of morning traffic replaced by an eerie silence.

"Kei, you okay?" Yui asked, noticing his distracted expression.

"Yeah," he replied quickly, shaking his head. "Just tired."

At school, Kei slipped into his usual routine, greeting classmates and helping a younger student who'd dropped their books in the hallway. Despite his quiet demeanor, Kei's kindness made him well-liked. Still, he preferred spending his time with Yui and focusing on his studies.

By the time the final bell rang, Kei was ready to head home. Yui walked beside him, chattering about her day. But as they reached the park near their neighborhood, Kei stopped in his tracks. For a split second, he saw it: a faint crack in the sky, jagged and glowing faintly before it disappeared.

"Kei?" Yui's voice brought him back.

"Nothing," he muttered, forcing a smile. "Just thought I saw something."

Yui tilted her head but shrugged it off. The two parted ways near Kei's house. As he opened the door, Hina greeted him with her usual enthusiasm, but Kei's mind lingered on the strange sight.

That night, as Kei lay in bed, staring at the ceiling, he couldn't shake the feeling that something was coming—something far beyond his understanding.

Outside, above the quiet town, the faint crack returned, pulsing faintly before vanishing into the darkness.