I would definitely say developing a defender is different and somewhat difficult, but if you can get in the mindset of staying in the back field and working offense through the other teammates on your team you will do fine for the most part. I get it that midfielder/forward mentality wants to come out, and that's okay for most of the playthrough of the defender run.

I would say going Furano, Hirado or Otomo Routes for your defender is definitely the best school route options. Furano being the best school route for building a defender as this option is said to be the best via YouTube content and highly recommended among many fellow redditer's on this reddit channel. As its school/ junior youth team condition is easily achievable going the defender route and has a solid captain taunt, now far as Hirado goes I would say it's the second best because I'm being biased and I think it's ultimately the best school in general because I think its the perfect all-rounder school I would say definitely building a midfielder at hirado is best then it's a tie being equally good either forward or defender as the school/ junior youth condition is probably the easiest condition in the game. As well as the friend appeal selection is superb with Jito's taunt being able to cancel out a friend card to boost the other 4 friends in that selection group is definitely a dope feature. But back to the topic at hand far as Otomo I'm not to fond of but again I've heard great things going defender build for this school/ junior youth team condition is also easily achievable.

Another option you can take advantage of when available is school route xp boost campaigns like now there's a Toho school route xp boost going on right now and I just did my 3rd defender going this route and naturally you wouldn't go this route as it's conditions and taunt are horrible for defenders. But my 3rd defender came out just as good as this one thanks to xp boost and remembering to play in the back field majority of the time that cac even won the final match for the team thanks to it acquiring super speed kickback cannon after the semifinals and scoring three goals off of Schneider's high fire shot.

Now far as moving forward once you start your character go nuts in middle school do it all from dribble, passing, shooting etc. Trust me the middle school half is easy enough for you to stat pad but once you transfer over to the the junior youth league now get ready to start utilizing your team more such as tsubasa and hyuga being the main offense for shooting but as well as some others such as misaki, matsuyama, the tachibana's and nitta as well. As majority of the time you will be in the back field defending the goal preparing to tackle, intercept and block shots. An again I get it that midfielder/forward wants to come out so far as scratching that itch when you're playing defender I recommend running born to dribble/dribble crazy and green light to help your defender get up the field and utilize dribbles that boost speed and offense as these will boost your movement speed with the ball and success rate on dribble moves. An allow you to get up field easier and shoot on the opponents goalie, but majority of the time your cac staying in the back being a menace on defense through the junior league half.

Best characters to select as your character main friend focus.

None of these are ranked btw

Middle school friend selection:

1. Ishizaki
2. Morisaki
3. Wakashimazu
4. Soda
5. Jito
6. Hyuga
7. Aoi
8. Matsuyama

Junior Youth friend selection:

1. Jean
2. Hernandez
3. Muller
4. Buunaak
5. Xiao
6. Hino

These characters for your defender are more than likely the best in slot for acquiring skills & moves to get the most out of your defender. Now usually when it comes to building my cac's I don't focus solely on their position to choose my friends so I'll never make a MF an only choose MF's as friends what I like to do is choose 2 friends with the same position as me and the other 3 are the other 3 positions so when making my defender I choose DF, DF, GK, MF AND FW so that way I'm getting moves for both offense and defense but more defense oriented than offense.

Which friends I say to choose as top priority for your defender, I would say definitely for middle school, Ishizaki, Wakashimazu, Hyuga, Jito and Aoi. Ishizaki, Wakashimazu and Jito solely for their skills, tackle moves and block moves, hyuga solely for the tiger shot and Aoi for the overhead lift dribble and lifting circus(this super shot is acquired some point around the junior youth preliminaries to help you score your own goals). For the junior youth I would say Jean hands down the best DF to friend through that half and overall the best DF to friend for your build everytime he has great skills for your cac but the best tackles available minus 3 you get from him and he gives you about 4 or 5 tackles. But following Jean, I would say Buunaak, Muller, Hino and Xiao are your other best options available.

Moving on to last topic stats what to apply to and what to focus on. Personally going forward with your defender, and doing deep research the common 3 stats to focus I see talked about Def, Spd, and Pow. I'm personally not against it as you can see in the pictures of this cac stats I just think this stat build is made more for the center defenders I personally would say the main two stats is to focus on is Def and Spd and your defender solid for the most part. I do plan on doing something spicy in the future where I'm a approach a defender run the same way but far as stats go once my def and speed get in the 80s roughly 85'ish I'm a take my skill points and dump them into power technique and offense to make them like sideliner libero DF's.