Danny Pink

Rupert "Danny" Pink was a sergeant in the British Army, who later became a mathematics teacher at Coal Hill School.

Instantly smitten with fellow teacher Clara Oswald, Danny ended up becoming her boyfriend due to some blundering on the Doctor's part.

Childhood
As a child, Rupert lived in West Country Children's Home in Gloucester for some time. He disliked his given name and wanted to change it to Danny when he got older. One night, he had a nightmare of someone under the bed grabbing his ankle, and he met the Twelfth Doctor and Clara Oswald for the first time. They encountered a figure which the Doctor believed might be a creature that hid under the bed. The three of them turned their backs so the creature could leave unseen. After it departed, Clara attempted to put the child at ease by placing toy soldiers to guard under his bed. She designated one of them — which Rupert had called "Dan the soldier man" — as the one in charge: a soldier so brave, he didn't need a gun. Rupert's mind was then scrambled by the Doctor to prevent remembrance of this encounter. He instead would only recall a dream where he was "Dan the soldier man". (TV: Listen)

Military career
Later in life, Rupert started going by the name Danny and joined the army. (TV: Into the Dalek)

He was a sergeant and served five years in both England and Afghanistan, (TV: The Caretaker) where he performed a number of humanitarian tasks, such as building wells, alongside traditional military work.(TV: Listen) After a having a particularly "bad day", Danny left the army. (TV: Kill the Moon)

Following his exit from the army, Danny became distressed when mention was made of him having killed while a soldier. (TV: Into the Dalek)

Maths teacher and relationship with Clara Oswald
Despite leaving the army, he established the Coal Hill Cadet Squad when he began working as a teacher at Coal Hill School. It was here that he was introduced to Clara Oswald by Mr Armitage. She invited him to join her at Kathy's retirement party after work that day, which he initially declined — an act he immediately regretted. While reviewing this awkward moment to himself, Clara overheard him. Although this further embarrassed him, Danny gratefully accepted her offer to grab a drink together. (TV: Into the Dalek)

The two went for a drink at some point later, with mixed results. The couple argued several times, and Clara left twice. After an adventure with the Doctor, Clara came to Danny's flat later that night, and, after the two apologised for their behaviour, they kissed for the first time. (TV: Listen)

Despite these difficulties, the two continued dating. They attempted to set up a date and share a kiss in an empty classroom, but were interrupted by a nosy student, causing both of them to scold, "OUT!" (TV: Time Heist) Clara, however, continued to have adventures with the Doctor (PROSE: The Crawling Terror, PROSE: The Blood Cell), which led to him being puzzled at Clara's occasional discombobulation, including one incident where he found her wearing a space helmet for some reason. (TV: The Caretaker)

Afterwards the Twelfth Doctor re-met Danny Pink as an adult, insisting that he was a PE teacher even after Danny said he was a maths teacher. Danny suspected the Doctor of doing malicious activity in Coal Hill when he found chronodyne generators scattered around the school. Thinking them to be weapons, he disabled some, unaware that the Doctor had strategically placed them to lure out a Skovox Blitzer which had taken up residence on Earth and draw it inside the Time Vortex. Because of this, he ran into the Blitzer itself and the robot was merely sent a day into the future. The Doctor chastised Danny for meddling even though he was doing what he believed was the right thing, and ran into his girlfriend, who had trouble explaining the truth about what was going on. Danny instantly concluded that the Blitzer was an extraterrestrial and thought the Doctor and Clara were from space.

He was half right, inevitably learning about the Doctor's alien origins and the TARDIS being bigger on the inside. Amazed and shaken up, he confronted Clara for leaving him in the dark about these details. She explained that she travelled with the Doctor to see wonders that she couldn't in her ordinary life.

Danny, curious about how Clara acted around the Doctor, tagged along with her onto the TARDIS to see if she behaved just the same or not. He snuck aboard using an invisibility watch given to him by Clara, snatched from the Doctor's own supplies. Danny realised the Doctor did not think highly of him and was repeatedly insulting his name. Danny deactivated his disguise, aware the Doctor had sniffed out his presence, after getting a tip-off from the Doctor's very pompous remarks about him. Irritated with the lack of respect he was given, Danny returned it. He provoked the Doctor's anger on purpose to gauge the true extent of his character.

However, the Doctor's opinion of Danny changed when he helped stop the Skovox Blitzer by drawing its fire long enough that the Doctor could command it to shut down with a self-built communication device, demonstrating his military training with a skilled somersault through the air. He entered better terms with the Doctor, and knew he had to prove himself a worthy boyfriend for Clara in the Doctor's eyes.

After learning the truth the Doctor and Clara's exploits, Danny warned Clara that he wanted her to stop lying or it would spell the end of their relationship. He had also met men like the Doctor before who pushed people to get stronger, and recognised the officer mentality in him. Because one pushed Danny too far and made him do something he regretted, he told Clara to make a promise with him- that if the Doctor broke her trust in him and did something similar, that she would immediately go to her boyfriend for help. (TV: The Caretaker)

When Clara returned from her adventure on the Moon near the beginning of a work day at Coal Hill School, a tired Danny saw her pacing about frenetically in a classroom. From the look on her face, Danny immediately knew that the betrayal of trust he dreaded had struck. He recognised her forlorn expression as the same one he had after his love for the army was tarnished- the moment he decided he no longer wanted to be a soldier.

Clara started to tell Danny what happened, but in her furious state, she revealed she was through putting up with the Doctor. Danny, unfazed at Clara's upset and frazzled mood, was prepared for this conversation to eventually take place. He stopped Clara from saying anything further, and contended that while she might have had a serious falling out with the Doctor, their relationship wasn't quite over yet, not as long as the Doctor could still make her angry. He likened it to the day he left the army, which he described as a "very bad day". Danny advised his girlfriend to explain everything after she had cooled down, so they could work through the problem steadily. Clara embraced him and admired how he had grown so wise from his experiences. (TV: Kill the Moon)

Danny was aware of Clara's supposed final outing with the Doctor; he called twice during the unexpected adventure on the Orient Express, believing that Clara would resume a normal life. However, she lied to him, instead choosing to continue her adventures with the Doctor in secret. (TV: Mummy on the Orient Express, Flatline)

Danny and Clara later took a class of "special" children on a camping trip to a London museum. To their shock the next morning, trees had grown all over the world overnight. Forced by Clara, Danny helped lead the group to the TARDIS to get the Docotr's help. Danny assisted by keeping an eye on the group while the Doctor and Clara investigated the situtaion; the trees had grown to protect the earth from an impending solar flare that would exterminate all life on earth. Though offered the chance to watch the event from space, Danny turned it down in favor of getting his class home. (TV: In the Forest of the Night)

Other references
Colonel Orson Pink, a time traveller who was originally from the 22nd century, bore a striking resemblance to Danny. When Orson took off his helmet, Clara thought it was Danny. According to "silly stories" told about one of Orson's great-grandparents, time travel ran in the family. (TV: Listen) According to the Twelfth Doctor, even though they had the same surname, Orson "[did]n't look anything like" Danny. Clara claimed that he looked "very like him". The Doctor responded, "Does he? I dunno. Who remembers a PE teacher?" (TV: The Caretaker)

Danny Pink Danny Pink