An honor student at the Afterlife school. He is a member of the SSS and contributes mainly with intelligence gathering.
Despite his attempts of acting smart, Takamatsu is really just as dumb as everyone else on the Battle Front. However because he wants to be taken seriously by all groups of people, he as furiously worked out to develop rippling muscles. After the first time he stripped in front of his class he has enjoyed it ever since and is constantly doing it at the most inappropriate times.
In the OVA for Angel Beats! Takamatsu constantly exclaims that "I've gotten beefed up just for this!" and strips. However, it is known that that is obviously not true. Also in the OVA we get to see more of his romantic side in his classes when he constantly yells about wanting to know the more romantic side of the subject.