Luffy from 'One Piece' is a great choice. His carefree yet determined personality would contrast well with Ippo's more serious and focused nature. They could bond over their shared love for adventure and fighting for what they believe in.
Definitely! The Hajime no Ippo manga has a compelling plot with lots of exciting boxing matches and emotional character arcs. The way it portrays the sport and the growth of the main character makes it really enjoyable.
Ippo's age in the manga changes as the plot progresses. At the beginning, he's around 16 or 17 years old. As the story continues, he gets older with each new arc.
One idea could be a crossover with 'Dragon Ball'. Ippo could train with Goku and learn some of his ki - based techniques. This would not only make Ippo stronger in the boxing ring but also introduce a new element to his fighting style.