Yea Honda owns Acura or vice versa, I dunno. But they are the same and one was built from the other, not bought. They call it Acura there and Honda here for marketing reasons, vehicle is the same.
Accord here sold from Honda Showrooms is the same sold in US showrooms. The Acura TSX isnt sold in PK brand new from an authorised dealer as per my knowledge.
Same with the following companies
Toyota & Lexus , example Toyota Land Cruiser Cygnus/ Lexus LX 470
Honda & Acura , example Honda Accord/ Acura TSX
Nissan & Infiniti , example Nissan Skyline/ Infiniti G35 Sedan~Coupe
Mercedes Benz & Maybach & Smart
BMW & Mini & Rolls Royce
Dodge & Chrysler & Jeep
--Please add to list--
Salam.