trying to find an animê but all i can remember is one character is red hair, wears headphones around his neck.

one particular, him and his 2 friends go to a museum (i believe) as their teach is looking for information on a secret computer. one scene he looks at something then sees a women from the past, who then runs through him, soon after he collapses and is sent to hospital with his friends and teacher. he dreams that he is this women where she is ill but awaiting her husband to return. i also remember that his friend would collect these cute key rings while he waited for his friend (maybe lover) to awaken from his trance. any help?