•Both Doraemon and Pikachu can communicate well with humans and certain non-humans(Doraemon can talk to normal cats,and Pikachu can talk to almost pokemons with their language).Both can control electricity(Doraemon can use gadgets such as Mini Thunder Cloud to do that) and improve their powers and abilities with gabgets(Doraemon can use gabgets such as super gloves to do that,and Pikachu is able to use different Z-Moves with Z-Crystal and Z-Ring).Both had been kidnapped by evil organizations and separated from Nobita/Ash(Doraemon was kidnapped by the Chamocha planet's robot army,and Pikachu was caught by the Rocket Team more than once).They each was chosen by a human in a chance, and met his best friend since of it(Doraemon stayed at Sewashi's house since Sewashi accidentally pressed the wrong button at the robot selection meeting,and he sent Doraemon to the twentieth century to take care of Nobita at later.Ash missed all the other assigned Pokémon because he woke up too late,so Pikachu became the only choice for him).They each used to plan to leave Nobita/Ash, but changed his mind when Nobita/Ash got him back(Doraemon planned to leave Nobita since he thought Dorami can take better care of him,but Nobita got him stayed.In the movie ‘’I Choose You!‘’,Pikachu planned to leave Ash since he blames it for causing him to lose the battle,but Ash reflected himself and got it back).They each showed his attachment to something,and finally his best friend found that the reason for this was related to their friendship(Doraemon once lost the bell on his collar and insisted on getting it back,then Nobita found that it's because Doraemon promised him that he would cherish the bell.In the movie ‘’I Choose You!‘’,Pikachu kept insisting that he wouldn't go into Ash's poke ball,and finally Pikachu told him that because he could stay with him all the time).Also,The blue-and-white cat and the yellow-and-black squirrel have just the right body color contrast.

Contrast:Whether Ash finally can become a master pokemon trainer with Pikachu remains to be seen,but it's certain that Doraemon has changed Nobita's future life in a good direction.