What does Takeshi mean?
A Japanese name whose meaning depends on the kanji chosen; it is commonly written with 武 'military, warrior' or 猛 'fierce'. The martial reading applies only to those characters.
What does Tatsuo mean?
Japanese given name read as 'dragon man' when written with a dragon element plus 'o/man', e.g. 竜雄 / 龍男 (竜/龍 'dragon' + o 'man/hero'). Hedge: strongly kanji-dependent; some spellings use 達 'attain' or other elements with no dragon sense, so only the 竜/龍/辰 writings genuinely mean dragon.