One weekend, after returning to the West Capital, John visited Bulma's house.
Bulma's mother warmly welcomed John, as always, with a bit of playful teasing.
John asked, "Auntie, are Bulma and Dr. Brief at home?"
"Oh, they're home. Bulma should be in her room watching TV, and your uncle is probably in the lab," Bulma's mother explained. "Do you know the way, or do you need me to find you a robot butler to guide you?"
John thanked her and said, "Thank you, Auntie, but I know the way. I've been here many times before." John was a frequent visitor to Bulma's house and was familiar with the layout of the rooms.
He arrived at Bulma's room and knocked on the door.
"Come in!" came Bulma's slightly irritated voice from inside.
"Bulma, what's wrong? You don't seem happy. Where's Yamcha?" John entered the room.
Bulma replied, "Hmph, him? He's at the Martial Arts Arena, sparring with others, trying to surpass you all in the next Martial Arts Tournament."
At this point, there was already a rift in the relationship between Bulma and Yamcha. Bulma wanted a gentle, understanding, and considerate boyfriend, but Yamcha was like a wild wolf, untamable and driven by his martial arts spirit.
Yamcha would eventually give up his pursuit of martial arts when he realized that no matter how hard he tried, he couldn't keep up with Goku and the others. It wasn't due to a lack of effort but his inherent limitations.
Feeling ashamed, Yamcha would disappear into the nightlife of the West Capital, take up baseball, and eventually part ways with Bulma.
John had never been optimistic about their relationship from the start, but he didn't want to interfere as he believed that matters of the heart should be resolved by the individuals involved.
After venting her frustrations, Bulma asked John, "By the way, what brings you here today?"
John replied, "I need your help with two things."
"Two things? Tell me about them, and if I'm not interested, I won't help," Bulma said, knowing that John would only ask for her assistance in creating a special machine.
John explained, "One of the things is something you can definitely help with, and the other will require some brainpower from you."
Intrigued, Bulma asked John to elaborate.
John continued, "The first thing is that I need a Dragon Radar."
"A Dragon Radar? Why? Do you want to make a wish to Shenron again?" Bulma asked, puzzled.
"No," John clarified. "I have other uses for the Dragon Radar, but please indulge me for now. I'd appreciate it if you could prepare one for me."
"Okay, tell me about the other thing you need help with," Bulma said nonchalantly. She knew that the Dragon Radar was a mature product and didn't require her personal involvement. The automatic equipment in her house could produce a Dragon Radar with just a computer command.
John continued, "The second thing is that I want you to help me build a gravity control room."
"A gravity control room?" Bulma asked, slightly confused. "A machine that can alter the gravity in a specific area?"
"Yes," John confirmed. "The gravity on Earth is a bit too light for me. I want you to help me build a machine that can increase the gravity in the surrounding environment, allowing me to continue training my body in a high-gravity environment."
"That's a great idea! If I can build a gravity room, Yamcha won't need to go elsewhere to train in martial arts. He can just train at home in the gravity room," Bulma said excitedly.
Hearing Bulma's words, John didn't have the heart to shatter her fantasy. He wanted to tell her that the problem between her and Yamcha wasn't solely about martial arts training.
"No problem, I'll take on this task. When do you need it by?" Bulma asked.
John replied, "It's not urgent. Just give me the Dragon Radar for now. As for the gravity room, I won't need it for another four or five months."
About a week later, John received a brand-new Dragon Radar.
John didn't set out to search for the Dragon Balls right away, as it would be another month before they would appear. Instead, he chose to stay in the West Capital to recuperate and prepare his body for the upcoming training journey.
(Do you know what John needs the Dragon Radar for?)
Time passed day by day, and John didn't engage in any training. Instead, he went to the outskirts of the West Capital, where he practiced balancing his body and energy while cultivating his mental fortitude.
Finally, on the 366th day after the last wish granted by Shenron, John located the seven Dragon Balls on the Dragon Radar.
"The Dragon Balls have finally transformed from Dragon Heads to Dragon Balls, and I'm ready to embark on a new training journey," John thought, already prepared for the upcoming training plan.
After more than a month, John visited Bulma's house again and asked for a plane capsule, a small submarine capsule, and several large storage capsules.
(Now you know what John is up to, right?)
Although it was strange that John requested so many large storage capsules, Bulma was currently preoccupied with the challenges of building the gravity control room and didn't question his intentions.
After everything was prepared, John bid farewell to Bulma's family and departed from the West Capital, flying towards Kame House in his plane.
It didn't take long for John to reach Kame House, where Krilin was undergoing his daily routine of 1,000 push-ups under Master Roshi's supervision.
As John landed his plane, Master Roshi curiously asked, "John, why are you here? I thought you were off on your adventures."
John respectfully bowed to Master Roshi and said, "Master Roshi, I'm here today to ask for the location of Karin Tower."
"Karin Tower?" Master Roshi was taken aback by John's request, as the tower was even more mysterious than the Dragon Balls, and most people didn't know its location.