How is กู (ku) rude? Is it just like the Japanese 俺 (ore)?

Before then, I heard saying ore is either rude or arrogant in Japanese to refer to yourself as ore. Just like when I tried to speak French and I pronounced moi as moy, they thought I was being rude but I was really trying to try out of French before I decided I hated it just as much as different pronunciations of words that looked a lot like English to me but a different language. So saying กู in Thai is rude too? And I thought Kanji symbols would appear but now all I get is a square on my screen!