Need help with character idea

[Sir cryosin]

Ok I want someone like a main character of a action anime someone that uses a katana aka longsword. But has little to no armor. He's quick, agile, but doesn't jump in and out of combat. I talked with my DM about letting a rouge used longswords with Sneak attack. Saying well it on the rouge prof weapon list. He said sure so I was thinking a longsword aka katana swashbuckler rouge but not all of its fluff feels right and it starting to feel mad with dex, str, con, char. I thought about monk and just using a longsword it won't hinder it too much but there is still MAD. So I an asking your thoughts and advice on this thank you giants.

Edited: as I picture someone the practice kendo.

[Gastronomie]

First off, kendo is not a practical martial art. People outside Japan seem to not even really know what kendo actually is, but one thing for sure it's not the badass "HITEN MITSURUGI RYU" stuff you see in Rurouni Kenshin and stuff like that. Not flashy, not efficient. So you should trash that idea, it's probably even not what you are thinking. You're probably thinking about "kenjutsu ryuha" (the respective groups of swordsmen who practiced sword-wielding in each of their own ways).

Rogues, especially Swashbuckler are exactly characters that jump in and out of combat, so that's probably not what you want. I actually think a Barbarian re-fluffed to be some sort of swordsman capable of enhancing his body for a limited amount of time (sorta like the HENSHIN stuff in anime) could work. Or it could be, more simply, a DEX-based Battle Master (Fighter).

[Arkhios]

If I was the DM, I wouldn't mind swapping longsword's versatility for finesse to make a katana.

[Naanomi]

Kendo (as a sport) involves use of armor that is probably somewhere between a breastplate and half-plate... A Battlemaster Fighter with higher than normal Dex for a Str fighter would do fine

[Shining Wrath]

First: can you live with refluffing a shortsword as the katana? If so, a Shadow Monk might work, dip Rogue to get Sneak Attack. Or just go straight Rogue and stick to leather armor.

Second: if you're sold on the longsword, then if I were your DM I'd play "let's make a deal". Here's your options as I see it - Monk based, or Rogue based.

Either way, you're adding longsword proficiency and you want to treat a longsword as a monk weapon / finesse weapon.

Monk based

Add Sneak Attack
Longsword


Rogue based

Add Monk's Wisdom Armor bonus
Longsword


Either way you're borrowing something important, even iconic, from another class. Now if I'm sitting in the DM chair and you ask for one of these combinations I'm going to ask for something in exchange which is also important and iconic. For the monk, I'm asking for some of your ki points - probably half of them. For a rogue, I'm asking for Expertise - you no longer get it. Also, to wield a longsword as a "finesse" weapon useful for sneak attacks requires strength - you will have to have a minimum of 12 strength on your character.

[TheProfessor85]

Go with Monk, way of the open hand. Replace open hand technique, with long sword proficiency and make it a monk weapon and perhaps a sunder/disarm effect using 2 ki point to do. Change the flavor of quivering palm to Secret Sword Technique: Delayed Death, rapid ten strikes. For more flavor make it active when you sheath the sword.

[Naanomi]

If you are looking at homebrewing, there are several monk 'kensai' subclasses floating around; starting with a martial weapon proficiency that counts as a monk weapon at 3, and progressing into a variety of option (Ki-fueled maneuvers, flurry with the weapon, etc)

[Specter]

If you're really set on this katana business, start as a Fighter with high STR and DEX at 14. That way, you get the most AC from breastplate and the option of wielding the sword with one or two hands. Battlemaster tool proficiency should go to calligrapher's tools for the samurai feel.

[Wulfskadi]

Try blade master monastic tradition. It's on this forum in the homebrew section under 5e

[gfishfunk]

Either go Monk with a short sword (say its a longsword), and add rogue if you want to be able to do sneak attack damage.

Instead, you can also do 1-2 levels of Barbarian to get Unarmored defense and refluff the Rage to be the typical anime "I'm now using my full power!" type of line.

Then, you can throw levels into fighter. It would work just fine.

[Lombra]

Barbarian-fighter multiclass seems appropriate: pump dex and con, wis is third in order of importance and dump the rest, you might want to get a level of rogue for expertise in athletics/acrobatics.
Refluff a rapier with slashing damage and you have an almost legit katana.
Dueling fighting style and battlemaster archetype are the best coices for the fighter, while a refluffed berserker is an ideal anime-power way to feel the character.