the nikaido family is as close-knit as they can be, sharing a majority of what's going on in their life with each other. her father (hiroshi) and mother (nanami) own a decently popular ramen store in the heart of shinjuku. her father is the epitome of dad, with his habits such as falling asleep on the couch while watching documentaries and his dad jokes, while her mother is more no-nonsense and strict, but loving all the same. despite being as close as they are and sharing a lot of things, tsuki is rather apprehensive about talking to them about her current situation with asami, since that'd mean she has to come out as lesbian to them and she doesn't know what her parents' stance on the lgbtq+ community is.

and then there's tsuki's younger brother, ryuunosuke, who she affectionately calls "ryuu-kun". born in 2002, while tsuki and ryuunosuke used to not get along as well when they were kids, as time passed and both of them got older and more mature, they're now inseparable, constantly calling, texting or video chatting with each other whenever they can and checking in on one another. if there's anyone in her family who knows, quite literally, everything about tsuki, she'd say it's her brother. ever the big fan of his older sister, ryuunosuke also decided to follow in tsuki's footsteps in becoming an idol, but in japan rather than korea. he auditioned for produce 101 japan 2 in 2021 and placed 9th in the final, thus granting him the chance to debut in the final group, ini as a lead rapper. (replacing ikezaki rihito)

being quite the affectionate individual despite her introverted disposition, tsuki gets along with the members of sixteen just fine. sixteen is her found family, her rides or dies, her best friends and closest companions, and once the members start getting closer and sixteen starts picking up more traction as a group, she more often than not ends up referring to them as her family. sure, twelve girls in one group doesn't automatically mean they're all close to each other, but it's not impossible, right? even then, out of the group, tsuki would say she's closest to the dance line since they work together a lot, with quyen being her best friend in the entire group.

here.

tsuki and seunghwa are somewhat close, even though they both have different social circles in sixteen, with seunghwa being closer to the vocal unit and tsuki being closer to the dance unit. still, they are close enough to do their own thing without the silence ever getting awkward between them, which speaks volumes about their friendship. even though they do have those moments, on stage together, they do tend to be quite awkward, especially when they're doing fanservice, so the members are usually quick to push the two together when it comes to "try not to cringe" games like the "i love you" game. despite the surface level of their friendship, tsuki wishes for a more profound closeness with seunghwa.

while tsuki's best friend in the entirety of sixteen is yuheon, momoka comes at a close second, as both her and tsuki a part of the dance line and the j-line of sixteen. even though most of their conversation topics at the start were dance, music and sometimes anime (and mind you, their tastes in anime differ ;a lot), momoka and tsuki soon come to realize that they have things and people they know in common as well, like pledis' very own shimizu eijirou aka eiji who is one of the first japanese people tsuki met in pledis and… let's say someone that holds a very important place in momoka's heart. tsuki appreciates momoka, her work ethic and her somewhat stern but still outspoken and witty personality a lot and she hopes the elder dancer appreciates her as well.

here.

here.

tsuki is aware of minju's respect for her, and honestly, she's flattered. a girl like minju? seeing her as a role model and aspiring to be like her? who wouldn't be flattered. in return, tsuki admires minju's boldness and openness, and wishes that she can be like her at times as well. tsuki and minju's relationship is built upon two main ideals: trust and respect. while they do have their own social groups in sixteen, with minju being closer to the vocal unit and tsuki being closer to the dance unit, whether they're viciously defending mint chocolate ice cream against the members that don't like it or helping each other out with vocals and dance, it's always a great time with the younger vocalist.

here.

with her eyes alight and heart aflutter, narae basks in the warmth of tsuki's affection. tsuki's tender care and doting gestures towards narae have definitely earned her the title of "narae's favorite unnie in sixteen". the fellow sixteen members affectionately dub them "the child and the bad influence aunt," a playful moniker that captures the essence of their relationship. tsuki, the endearing "aunt," delights in spoiling narae to the fullest, while narae, the cherished "child," revels in the attention and care bestowed upon her, even though tsuki doesn't hesitate to be strict with her as well if necessary.

it'd be safe to say that tsuki admires seventeen as a whole. she admires their work ethic, their closeness, all the members, their personalities, their individual talents, everything. some idols would sometimes mention their company seniors as their role models for the sake of formality, but seventeen are tsuki's true and genuine role models. out of all of the members, she'd say she's closest to jun and dino, the former because he's her mentor and one of the first people she met in pledis, and the latter because they're the same age.

from the outside, their relationship seemed like a picture-perfect love story. they were introduced by seventeen's jun, who, bless his heart, introduced tsuki to new pledis trainee asami as soon as he learned that asami was also japanese, thinking that they'd be close friends. time passed, they grew comfortable with each other and tsuki realized she genuinely started liking asami. and she came out to asami as a lesbian, which asami responded by saying she was pan and had feelings for tsuki. and thus, their connection bloomed in secret, hidden from the prying eyes of the other trainees and the pledis entertainment higher-ups.

 

what had started as a whirlwind romance between nikaido tsuki and yukimura asami now feels like a suffocating cage from which tsuki yearns to break free. at first, asami's affection felt like a warm embrace, a beacon of light in tsuki's tumultuous world. but as time passed, that warmth turned scalding, searing tsuki's spirit with every cruel word and controlling gesture. asami's own insecurities about herself morphed into weapons, aimed directly at tsuki's vulnerable heart.

 

every disagreement escalated into a battleground, with tsuki always emerging bruised and battered, her self-esteem crumbling with each verbal assault. yet, she clung to the remnants of their love, hoping against hope that things would change, that asami would see the damage she was causing.

 

but change never came. instead, tsuki found herself drowning in a sea of doubt and fear, her every move scrutinized, her every decision questioned. especially with asami leaving pledis, joining fantagio to become an actress and tsuki's impending debut in sixteen, asami's jealousy knew no bounds, casting a shadow over every interaction tsuki had with others, suffocating any semblance of freedom she once possessed. and now, tsuki is stuck in a room with seemingly no exit door and is trying to get out.

shimizu eijirou is tsuki's platonic soulmate and best guy friend. they first met when eiji first joined pledis in 2015, a year after tsuki joined pledis. while both of them communicated in korean for a good amount of time as tsuki showed eiji around, when the time to exchange names finally came, the names "shimizu eijirou" and "nikaido tsuki" were both met with a surprising "yOU ARE JAPANESE?!" in loud japanese, which made some trainees that were passing by them look at them in surprise. as they sat down for tea later on in one of the practice rooms, they got to know each other, talking in animated japanese and finding out that they only lived about 20 minutes away from each other in tokyo, with eiji being from shibuya and tsuki being from shinjuku, and frequenting the same places but never once running into each other. this meeting planted the seeds of a beautiful friendship that would last to this day. eiji and tsuki are each other's confidants and biggest hypemen, with tsuki being one of the people to send a video asking for the national producers to vote for eiji during produce x 101 and eiji's full support going into 16tv and sixteen wishes to debut. eiji knows how it feels to be stuck in a toxic relationship because he himself was in one until a few years ago, and he, along with jun and, later on, the other sixteen members, is actively trying to help tsuki find a way to break up with asami. eiji took place in produce x 101, representing pledis entertainment and ranked 5th in the final episode, debuting as a member of x1. however, after the rigging scandals and the subsequent disbandment of x1, pledis debuted him as a soloist under the stage name "eiji". (replacing woodz)