Sister

Sister is an ex-soldier who runs the chapel under the bridge.

His job under the bridge is to hold mass and maintain the chapel built in the river basin. His military background has made him paranoid, so he is almost always heavily armed and comically blasé about weapons.

Before coming to Arakawa, Sister used to work in an orphanage in England. One of the children he watched there was Stella. He taught her and the other children the game "Fight Club."

Sister is in love with Maria. Though Maria is constantly cruel to Sister, it is joked that Sister worships her like the biblical Mary. Though Sister's love appears to be entirely unrequited, it is revealed that the two of them have a long and extremely classified history from their days on the battlefield. Whenever Maria insults Sister, the wound on his face opens and bleeds dramatically.

Sister is one of the only people who know the Village Chief's secret of how Nino came to be under the bridge. It is implied that Sister and Maria both may have been involved with the incident as there is a flashback of the two of them standing with a young Nino and the Chief, but it is unexplained how this would fit in with the timeline of the story.

Appearance
Sister is 208 cm tall (a whopping six foot ten) and has a muscular build due to his military training. He has blue eyes, a battle scar on his right cheek, and short blonde hair that sticks out of his habit to frame his face. Underneath the habit, he wears army pants and boots. Though Sister wears the garb of a Catholic nun, the cross he wears on his neck and adorns the church with is an Orthodox cross. This is possibly meant to play on the joke of Sister's duality – a violent nun, an Orthodox Christian dressed as a Catholic. In a flashback, he is seen wearing a uniform that looks similar to a contemporary German military uniform.

Personality
Sister is a living contradiction. Despite being a holy man, he is always armed to the teeth and longing for the thrill of battle. He dresses like a Catholic nun but wears the Orthodox cross. He is in love with Maria, who is the complete antithesis of his biblical namesake. He seems to be genuinely religious, but often misquotes the bible and for some reason seems to picture God as Solid Snake from Metal Gear. The masses he holds are short and generally consist of him firing off a machine gun and asking if anyone has done anything wrong. If the answer is no, they do some brief bible themed exercise drills and then Sister sends them off with bags of homemade cookies.

Sister seems to have symptoms of PTSD from his time in the military, and as such is very paranoid. He often boobytraps the river basin to keep out intruders, and nearly always has a gun on his person. He's the only person under the bridge who is able to see Last Samurai's sword when he uses it for haircuts, and he struggles to stay still rather than dodge it. At one point, he spends the night baking a giant (and gorily decorated) cake because he woke from a nightmare that kept him up for the rest of the night. At the same time, he claims to miss the thrill of battle so much that he sleeps holding an unexploded bomb. He and Maria also react to seeing the river residents tearing down a statue of Kou with comical nostalgia.

He is also extremely serious about physical training and took great offense at the Tengu's fake gym. He created a training room of his own for his friends to use, but no one could join him because there were no weights under 100 kg. When it snows, he likes to challenge himself by having people strand themselves on a makeshift mountain for him to rescue them, and during the annual marathon, he turned it into another personal challenge to run it while carrying heavy military equipment and pretending both his legs were broken.

In spite of his toughness, Sister is a surprisingly gentle soul. As he used to run an orphanage, he is often seen caring for Stella and/or the Iron Brothers, who all love him a great deal. Though there are several gags regarding Sister raising the children like soldiers and encouraging them to train their muscles rather than play like normal kids, it seems that making sure the children (and even the adults living under the bridge) grow up to be strong is his way of showing love.

He is a talented cook, particularly when it comes to baking. He always makes homemade cookies to give out at mass, and P-ko once remarked that once you taste his cakes, you can never go back. He also tends to a beautiful flower garden in the chapel that he grew himself. When it comes to his crush on Maria, Sister is painfully shy and often gets flustered, even to the point of using a grenade to make a hole for himself to literally crawl into.

Sister genuinely cares about everyone under the bridge, and in spite of his habit of misquoting the bible, he often gives surprisingly heartfelt advice or comfort. When Nino repeats something that Sister told her when she was younger, Sister appears genuinely touched.

Like many of the people living under the river basin, the role that Sister chose to play says more about him than how faithfully he plays it. Just as Hoshi wears a star-shaped mask because he wishes to be Nino's personal evening star, Sister continuing life as a nun and running a church by the river suggests that deep down, he wants to be a person who is gentle and caring and that this is the truest expression of himself.

Background
Sister comes from a military background, though it is never stated what country he fought for or even what war he took part in. Sister's nationality, in general, is ambiguous; Though he ran an orphanage in England, he wears the Russian Orthodox cross and in flashback, he is seen wearing a uniform that looks more similar to a German army uniform. he also uses the fake name "Franz" when pretending to be a member of Kou Ichinomiya's staff. His special forces background makes it likely that he has lived all over Europe at one time or another and possibly had many identities.

Much of Sister's past seems to be top secret, and he rarely talks about it, only giving the river residents (and readers) comically absurd glimpses of his past out of context; For instance, when Kou asked if Sister had ever been in love, Sister casually replied that everyone has been in love once or twice and that it is bittersweet like "a forbidden love born in the gap between life and death," with a flashback of him holding a dying soldier in his arms.

At some point during his service, he met Maria on the battlefield and fell in love again. The two of them were together for three years, and Sister leaked information to her that cost Sister's side the war. It is never stated whether Maria had simply been using Sister for information or if their relationship ended for some other reason, but in the end of the manga, it is implied that Maria once lived at the orphanage with Sister, suggesting that the two of them were together even after the war ended.

It is also suggested that Sister and Maria may have come to the river basin together at the request of the Village Chief, as the two of them are the only ones who know the secret of how Nino came to live under the bridge. Sister claims to owe the Mayor a great debt and dotes on him because of it, but it is unknown what that debt is or whether it was incurred before or after Sister came to the river – however, it is possible that Sister is referring to the Mayor seeing to it that the orphanage was taken care of in his absence. In a flashback where Stella mentions the new head of the orphanage, he seems to be referring to a man who looks very similar to the Chief's true identity.

Relationships

 * Nino: Sister is very protective of Nino, even going so far as to covertly observe her new boyfriend for a week, prepared to shoot him if he hurt Nino. Like everyone else in the river basin, Sister is deeply fond of Nino and glad to see her smiling after she starts dating Kou Ichinomiya. He is one of the few people who know the circumstances of Nino coming to live under the bridge, and as such is dedicated to keeping her safe. At some point, he told Nino that she was like a bridge missing its pillars and that she would need to find something to replace them to keep on living, no matter how strange that replacement was. Those words apparently were important to Nino, because she repeated them later in life, causing Sister to be shocked and touched that Nino remembered them.
 * Maria: Sister is in love with Maria. The two of them share a history on the battlefield, and once we're in a three-year-long relationship and may have even been engaged. However, the relationship ended for unspecified reasons (possibly because Maria only wanted information) and now she treats Sister with contempt. Since Maria enjoys insulting people to get a rise out of them, Sister's stoicism annoys her. As such, she is more sadistic toward Sister than anyone else, going so far as to call him a pervert and intentionally toy with his heart. Though Sister was trained to withstand torture, Maria's insults are the one thing that gets under his skin – likewise, on the rare occasions when Sister embarrasses Maria, Maria reacts very strongly. The battle scar on the right side of Sister's face could have been given to him by Maria, as he does not have the scar in the flashback of their first meeting, and the wound reopens only when Maria insults Sister. In spite of Maria's cruelty, Sister doesn't believe that she is a bad person (an opinion shared by Kou Ichinomiya). Sister's love at times approaches worship, as he will insert Maria into bible stories and keeps a diary of the things that Maria says, which he likens to the books of the bible. When Maria gave Sister a gift of lingerie in an attempt to humiliate him, Sister put it up in the church and prayed to it, touched that Maria had finally given him a gift. And when Maria thanked Sister for a bouquet of flowers (cistus, meaning "I will die tomorrow" in flower language), Sister worked even harder at tending his flower garden. However, the two of them do occasionally get along, usually whenever they get to cause mayhem together akin to what they experienced on the battlefield. Sister and Maria are also both the only people trusted with the Village Chief's secret and seem to be able to put their differences aside when it comes to protecting Nino.

Quotes

 * "Orders from Sister... EVERYONE! LINE UP!"
 * "I didn't mean to be mean... I just wanted to see the tears in your eyes."
 * "School uniforms and machine guns go together."
 * "Ha ha ha, quit fighting, you two. Unless you want to settle this in the next life?"
 * "That's right! Soldiers can specialize in infiltration, assault, or support! They shouldn't compare their own attack power to other armies!"
 * "He's mastered holy muscles!"
 * "Hurry up and give me instructions if you value your life."
 * "I'm handing out chocolate! Let this one piece sustain you through another Valentine's!"
 * "I suppose I fall asleep holding something as well... What I'm missing... is the thrill of battle. So I sleep holding an unexploded bomb."
 * "Improve yourself, and you can treat your enemies with kindness. I can kill him anytime I choose... That confidence allows me to remain calm and be nice."
 * "'If someone slaps you on the cheek, turn to them the other. If someone tries to sue you and take your shirt, hand over your coat as well.' To these words, Maria replied, 'He seems very punchable.'"
 * "She allows me to be this close to her... without ending my useless life. She truly is a woman of mercy."
 * "I wear this all the time. But now I'm going to give this cross to him. God has saved my body and soul so many times. I'm sure He'll protect Rec, too."
 * "Nino, right now... you're like a bridge missing half its pillars. Find something to replace them. It won't take the same shape, but... whatever shape it does take, you'll need it to live."