To say Jagi had tunnel vision wouldn't be entirely accurate. The boy did have the ability to focus in on one thing incredibly strongly, but his short coming was the fact this focus was more often than not, short-sighted and easily changeable. So while one day it might be his biggest goal to get his father to accept him as a student above his brothers, the next day he didn't need any of them, and was as determined to succeed entirely on his own. On top of that, he wasn't willing to wait for his results. If he couldn't see something coming out of what he was aiming for fairly soon, it was likely he would change his approach or give up on whatever it was entirely and start something else. It wasn't at all that he was lazy about getting what he wanted-- he was willing to work hard-- but that his thirst for progress was immature.
On top of that was the fact that there was still an average sixteen year old boy in that body of one being trained for great things, so conflict was inevitable. Toki said something like: It's dangerous, you'll hurt yourself if you try that but Jagi only heard: You can't do it, you're not as good as me. Kenshiro would apologize; his younger brother's pity is the last thing Jagi wanted. All of his brothers rubbed him the wrong way, but Raoh was the worst-- Raoh said the least out of all of them. For someone like Jagi, who needed to hear a person's words to even begin to understand them, this was the worst. To Jagi, Raoh was arrogant, condescending, self-righteous, smug, selfish, an all around grade A asshole. With their father always taking everyone's side but Jagi's, it was only so long before he would of exploded if he hadn't ran off like he did. Last time, he'd used that time off to go hang out with Anna and the others, but this time he could at least see far enough ahead to envision a time when he would come back to the dojo. Come back stronger, and make everyone realize it was him, Ryuken's first son, who deserved everything they were now stealing away from him.
Training by himself did wonders for Jagi's spirit. Without that visible competition, he could rate his progress by how he felt he was doing, and he assessed that to be 'pretty damn good'. Mostly during those months, he camped in the woods far away from the city, from the dojo. Sometimes Ryuken brought his students out here to train, which is why Jagi thought to go that direction at all, but not this far. They wouldn't discover him (he alternated from being sure they would be looking for him and not wanting them to find him, and feeling totally abandoned by the fact they probably weren't). For the first couple of weeks, that solitude was mostly grand, and probably exactly what he needed. But around the second or third month, he missed having his brothers to argue with, having someone to insult and criticize and take a couple swings at-- routine associated these feelings with family. He didn't have anyone to talk to out here--subtract for himself, and he was plenty vocal in that respect-- but any time those kind of thoughts popped up, he reminded himself more clearly of their mocking faces, and then he didn't miss them at all anymore. It also caused him to work at his training that much harder, thinking of those faces. Some of it was just him spinning his wheels, which he couldn't realize without someone else there to evaluate him. But it wasn't all for naught either: one afternoon, he was finally able to precisely strike one of the small leaves he'd caused to fall down from the tree top above him. Toki was able hit over half of them, when he did this exercise, but seeing one is enough to make Jagi grin proudly at the fact he was clearly getting somewhere. "All right!" he laughed at his victory, "When I tell Anna, she'll..."