Osakana Nemu / LunatheMagikarp (Vtuber) | Illustrious

• Main design:

nemufeesh,
blue eyes, pointy ears, mini crown, ahoge, blue hair, purple tips, blunt ends, long hair, low twintails, necklace,
white shirt, single off shoulder,
bike shorts,
black socks, sneakers, converse

black crop top is also a relevant tag for this design, but it should usually get generated as part of her outfit (specifically the white shirt) without the need for the tag itself to be in the prompt.

• Athletic design:

athlefeesh,
blue eyes, pointy ears, blue hair, purple tips, blunt ends, short hair, necklace, headphones around neck,
red cap, sideways hat,
bandaid on arm, bandaid on face,
crop top, midriff, navel, single fingerless glove, pink single wristband, thumb ring,
pink pants, open fly, clothes around waist, wallet chain,
white shoes

• Princess design:

prncssfeesh,
blue eyes, pointy ears, tiara, ahoge, blue hair, purple tips, blunt ends, jewelry, earrings, short hair, blue festoon (necklace),
strapless dress, single detached sleeve, single wide sleeve, evening gown, layered skirt, dress flowers,
single bridal gauntlet, sleeve past finger, asymmetrical sleeves,
side slit, gladiator sandals, footwear flower

• Kigurumi/onesie design:

kigufeesh,
blue eyes, pointy ears, mini crown, ahoge, blue hair, purple tips, blunt ends, short hair, necklace,
onesie, kigurumi, shorts, buttons, short over long sleeves, gloved sleeves, fingerless,
uneven legwear, thighhighs, kneehighs, animal slippers,

hood up

hood down

• Witch design:

nemuweetch,
blue eyes, pointy ears, witch hat, frilled hat, blue hair, purple tips, blunt ends, long hair, twintails, necklace,
turtleneck leotard, cleavage cutout,
white jacket, single off shoulder,
orange skirt, pleated skirt, loose belt,
zettai ryouiki, orange thighhighs, knee boots

glasses, round eyewear

• Hairstyles:

long hair, low twintails

short hair

long hair, twintails

You should be able to mix and match details from each no problem, the activation tags are mostly there to reinforce each design in case just the individual tags aren't doing the job