Riku had returned the hug in large part because he didn't want to let her go. Though on some level he did wonder if he was more harm than good to her, potentially. Even then, he still couldn't quite let her go, and he felt some guilt over that selfishness. Holding her, and her wanting to be held was proof he hadn't lost her, which held a large degree of relief.

The statement about being scared didn't phase Riku in the way it normally might have. While he might've pointed out that was further proof of her having a heart normally, to Riku at the moment, Namine was just like any girl, but to him, very special. Right now, she wasn't a Nobody, but somebody to be protected, be it from fear or injury. At her shudder he gently ran his hand over her back, trying to comfort her.

Regardless, however, the answer held pain. Riku was never one to run from his problems, facing them head-on, despite what lay ahead. He responded to her by holding her a little tighter and bringing his head down further in a very protective embrace. With a swallow, Riku spoke quietly to her. "Then I'm... I'm sorry. I'm... so. So sorry."

It was very very rare to hear an apology from Riku, and it sounded like it was an alien word on his tongue, even if it was sincere. For him, actions spoke louder than words, and while he rarely said he was sorry, he would certainly act with regret, shame, and the drive to make amends. The flowers he'd lost sleep and meals to were that gesture, but with them incomplete and her willingness to forgive him even after he'd managed to worry her, it seemed like the only appropriate option.

And while he'd felt that shudder, she could also feel his body tense.