Sure! Since you want the story in Bengali but typed in English (Romanized Bengali), here is the full story of Aryan and Nila for you. I've expanded it a bit to give it that "long story" feel you're looking for.
Neel Khamer Shobdo (The Words of the Blue Envelope)
1. Porichoyer Shuru
Kolkatar ek brishtibheja bikel. Park Street-er ekta chhoto kofishope boshe chhilo Aryan. Aryan chilo ektu shanto swobhaber, boiyer patay dube thaktei shey beshi bhalobashto. Onnodiye Nila chilo prancholl, hashikhushi ek meye, je shob somoy nijer charpashe anondo chhoriye dito.
Sedin Aryan jokhon tar laptop-e kaj korchhilo, hothat tebiler upor rakha kofita ulte gelo tar diary-r upor. Thik tokhoni pashe bosha Nila nijer tissue egiye diye bollo, "Areh, sabdhane! Apnar diary-ta toh bhije gelo."
Aryan kichuta oproti-voh hoye takalo. Nilar chokher shei snigdhota dekhe shey ek muhurter jonno stobdho hoye giyechhilo. Ebhabei shuru hoyechhilo tader alap.
2. Bondhuttwer Gobhirota
Dhire dhire tader dekha howa barte laglo. College Street-er boiyer dokan theke Gongar ghat—shob jaygay tara ekshathe ghure berato. Aryan takey nijer lekha kobita shonato, ar Nila shonato tar chhelebelar dushtumir golpo.
Nila ekdin jiggasha korlo, "Aryan, tumi keno shob somoy ei neel diary-te lekho?"
Aryan heshe bollo, "Karon neel rongta amar khub priyo. Eta onekta akasher moto bishal ar gobhir." Nila heshe utthor dilo, "Tahole amio ki oi akasher ekta chhoto tara hote pari?" Aryan shudhu mridu heshechhilo.
3. Durottwer Bedona
Hothat ekdin Aryan-er babar bodlir khobor elo. Takey shohor chhere Onek dure chole jete hobe. Nila khoborta shune khub bhenge porlo. Sedin Gongar ghate tara dujonei chupchap boshe chhilo. Akash-e tokhon megher ghonoghota.
Nila bollo, "Tumi chole gele amake kobita ke shonabe? Ei shohor toh amar kachhe khali hoye jabe."
Aryan tar hat dhore bollo, "Durottwo kokhono moner tan komate pare na, Nila. Ami tomake chithi likhbo. Neel khame bhore pathabo amar shob onubhuti. Protita shobdo tomake amar kotha mone koriye debe."
4. Neel Khamer Opekkha
Shuru holo chithir adan-prodan. Aryan dure thakleo tader moner durottwo komoni. Proti soptaho-e ekta kore neel kham Nilar thikanay pouchhato. Shei chithite thakto Aryan-er notun kono kobita othoba tar sharadiner obhiggotar kotha.
Nila-o dirgho chithi likhto. Chithir shei shobdoguloi chhilo tader tike thakar rosod. Ebhabei kete gelo tinte bochhor. Phone call ba text message-er juge-o tara shei purono amej-ei bhalobasha bachiye rekhechhilo. Nila protita neel kham jotiye rakhto ekta kath-er bakshe.
5. Fire Asha ebong Milon
Obosheshe Aryan fire elo Kolkatay. Brishtir ek shondhyay shey thik shei kofishope Nilar jonno opekkha korchhilo. Nila jokhon bhetore dhuklo, dekhlo Aryan hate ekta notun neel kham niye boshe ache.
Nila chhute giye bollo, "Ar kono chithi noy, ebar shudhu shamna-shamni kotha hobe. Onek hoyeche ei neel khamer khela!"
Aryan khamta khule tar bhetore thaka ekta chhoto angti ber korlo ebong bollo, "Ei chithir shesh lineti chhilo—Tumi ki shara jibon amar kobitar chhondo hoye thakbe?"
Nilar chokhe tokhon jol, kintu mukhe chhilo ek ujjwol hashi. Shey shudhu matha nariye 'Hyan' bollo. Kolkatar shei brishtir dine tader notun ek golpo shuru holo, jekhane durotto noy, shudhu kachhe thakar golpo