Sensha Otoko: A True Tank Story is a parody of "Densha Otoko" that was part of the moon.cinemas.jp 2009 April Fools' Day joke. Adapted to manga format by Haruno Tomoya and included in TYPE-MOON 10th Anniversary Phantasm artbook.

Description (via TM wikia):
"A story about a 212cm military otaku with "Sensha Otoko" as his handle name. Despite his huge and imposing appearance, he is actually very shy, and thus had no girlfriends. One day, he saves a teenage girl from being harassed and promptly fell in love with the girl. However, because he has no experience in romance, he consults his otaku friends on the web-board Eirei Throne-Channel for advice."