Mika discovers this when they're on their way home from a day out. They're enjoying one another's company, walking side by side in comfortable silence when thunder explodes overhead. Yuu flinches violently and clings to Mika. Mika is confused at first, and Yuu brushes off his concern with a, "It's nothing, I just wanted to link arms with you, that's all." Because goddamn it, it's embarrassing.

They keep walking, Yuu tense as a crushed spring, and Mika is about to ask him what's wrong again when thunder screams and lightning flashes once again.

Yuu lets out the smallest of whines and pushes himself closer to Mika, grabbing his arm in a vice. He realises what's going on: Yuu is afraid of the thunder. Mika's heart squeezes in his chest. Rather than laughing, he just wants to hold Yuu.

"Yuu," Mika says. "It'll be okay."

Yuu clenches his jaw and longs to die.

"I know that, damn it. It's just a fucking -" Another thunderclap cuts him off.

Yuu is breathing hard and fast and staring wide-eyed at the ground, and Mika can't stand it anymore. It starts to rain. Mika wraps his arms around Yuu and Yuu faces Mika in his embrace, pressing his face into the crook of Mika's neck.

"Sorry. I know it's stupid." Yuu whispers above the pitter patter of rain.

He flinches at yet another clap of thunder and hides his face from the world.

"It's not, Yuu-chan," Mika says, stroking his hand soothingly through Yuu's dampening hair. "Everyone has their fears."

One of mine, for example, is losing you, Mika thinks.

Then Mika pulls back and tugs on his hand.

"Come on!"

They run all the way home and end up drenched to the bone. Yuu watches Mika as he laughs along the way. When Mika notices Yuu's gaze, he grins at him. Yuu still flinches at every thunderclap, but it's less scary with Mika by his side.

Yuu is gasping for air by the time they reach their doorstep. He's exhilarated beyond belief, heart pounding hard in his chest. He starts to laugh, too, and Mika laughs breathlessly along with him.

Yuu is a little less scared of thunderstorms after that day. As long as Mika is around, that is.

Now, they use stormy weather as an excuse to cuddle. Not that they need one, but the weather is perfect for it. They build pillow forts. They watch movies. They make love.

Yuu finds out that distractions are very effective for lessening the fear.

Mika finds out storms can be very rewarding indeed.